Brain fog and hypothyroidism

A publication of the American Thyroid Association

Summaries for the Public from Clinical Thyroidology (from recent articles in Clinical Thyroidology)
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Hypothyroidism is not associated with mild cognitive impairment in elderly patients


Hypothyroidism: a condition where the thyroid gland is underactive and doesn’t produce enough thyroid hormone. Treatment requires taking thyroid hormone pills.

Subclinical Hypothyroidism: a mild form of hypothyroidism where the only abnormal hormone level is an increased TSH. There is controversy as to whether this should be treated or not.

Thyroid hormone therapy: patients with hypothy-roidism are most often treated with Levothyroxine in order to return their thyroid hormone levels to normal. Replacement therapy means the goal is a TSH in the normal range and is the usual therapy.

TSH: thyroid stimulating hormone — produced by the pituitary gland that regulates thyroid function; also the best screening test to determine if the thyroid is functioning normally.

Thyroxine (T4): the major hormone produced by the thyroid gland. T4 gets converted to the active hormone T3 in various tissues in the body.

Symptoms of hypothyroidism in adults can include cognitive problems such as decreased memory, depressed mood and a general mental slowing. Treatment with thyroid hormone causes resolution of these symptoms if their only cause was hypothyroidism. In the elderly, there are multiple causes for cognitive problems other than hypothyroidism. Several studies have examined associations between hypothyroidism and cognitive problems in the elderly with mixed results. The aim of this study was to examine associations between mild cognitive impairment and hypothyroidism in an elderly population.

Parsaik AK et al Hypothyroidism and risk of mild cognitive impairment in elderly persons: a population-based study. JAMA Neurol. December 30, 2013

This was a population-based study that included 1904 eligible individuals from the 2004 Mayo Clinic Olmsted Study of Aging cohort, aged 70-89 years old on October 1, 2004. Baseline evaluations were conducted between 2004 and 2007, including demographics and presence of concomitant diseases. Mild cognitive impairment was diagnosed by consensus between the evaluating physician, nurse and neuropsychologist based on absence of dementia, memory concerns and impairment in one or more cognitive domains on psychological testing. Clinical hypothyroidism was defined as documentation of thyroid hormone replacement therapy and/or a TSH ≥10 mIU/L with a low free T4. Subclinical hypothyroidism was defined as a TSH <10 mIU/L, normal free T4 and no history of thyroid hormone replacement.

Of the 1904 patients included in the analyses, 316 were diagnosed with mild cognitive impairment, 313 with clinical hypothyroidism and 141 with subclinical hypothyroidism. No associations were found between either clinical or subclinical hypothyroidism and the presence of mild cognitive impairment.

This study showed no associations between hypothyroidism and mild cognitive impairment in this large population of elderly patients. However, the results are limited by a lack of information on adequacy of treatment in the group with clinical hypothyroidism, so many patients that would adequately treated were included in the hypothyroid group. Assuming that most patients are adequately treated, this study indicates that there is not permanent cognitive impairment in patients with hypothyroidism. In light of the conflicting results of observational studies to date, screening of patients with newly diagnosed cognitive impairment for hypothyroidism remains a reasonable approach.

—Maria Papaleontiou, MD



Thyroid and the Elderly:

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Many people with thyroid and autoimmune thyroid conditions have problems with memory loss, as well as difficulty concentrating. This affects people with both hypothyroidism and hyperthyroidism, as well as autoimmune thyroid conditions such as Graves’ Disease and Hashimoto’s Thyroiditis. This problem frequently is due to the imbalance involving thyroid hormone, although it can be due to other factors as well. On both my male and female health history questionnaires, I have a place where my patients can check off whether or not they have memory or concentration problems, and I’d guess that about 60 to 70% of my patients check off at least one of these.

Upon following a natural treatment protocol, these problems can usually be corrected. But it’s important to understand that just balancing thyroid hormone levels alone won’t always help with memory and concentration issues. There are many people taking thyroid hormone or antithyroid medication who experience memory loss and have difficulty concentrating. So while balancing one’s thyroid hormone levels is essential, doing this alone is usually not enough.

Eating Well Is Essential For Memory And Concentration

It is very common to consult with a patient with hypothyroidism or hyperthyroidism who is taking thyroid medication, but at the same time is eating too many refined foods. I realize it can be very difficult to eat well, as it’s much easier to grab some fast food or munch on a bag of potato chips as a snack. And while doing this every now and then isn’t too big of a deal, doing this on a regular basis will affect your health, and can definitely have a big impact on memory and concentration.

So many people who are experiencing memory loss and/or difficulty concentrating notice a big difference simply by eating healthier. Cutting out or at least reducing the amount of refined foods you eat, and consuming mostly whole foods will make a big difference. Also, try to avoid drinking sugary beverages as well (sodas, fruit juice, sweet tea, etc.), and drink mostly purified water. Cutting out common food allergens such as gluten, dairy, and unfermented soy can also help greatly.

Can Taking Nutritional Supplements & Herbs Help With Memory Loss And Concentration?

Many people try to address different conditions by taking nutritional supplements and herbs. And while there definitely are supplements and herbs which can help with memory loss and concentration, the goal really should be to get to the underlying cause of the disorder. So while I’m going to list some herbs which can help, keep in mind that these typically won’t offer a permanent cure for memory and concentration problems:

Herb #1: Ginkgo. This is the primary herb I recommend for people who have memory loss and difficulty concentrating. I personally take it myself every now and then to help me focus better. For example, on days when I conduct a webinar I will take a few tablets of Ginkgo.

Herb #2: Bacopa. This is another very useful herb for memory and concentration. It is an Ayurvedic herb that also helps with immunity, and has been used to help with conditions such as Alzheimer’s Disease and depression.

Herb #3: Korean Ginseng. A good herb for mental clarity, although it has many other functions as well. Even though I listed it here, I usually will recommend either the Gingko or Bacopa first for problems with memory and/or concentrating.

Address Other Types Of Hormone Imbalances

While most endocrinologists and other types of medical doctors will focus solely on balancing a person’s thyroid hormone levels, people with hypothyroidism and hyperthyroidism frequently have other hormone imbalances as well. It’s not uncommon to have imbalances in estrogen, progesterone, testosterone, as well as other hormones. This is why some people will benefit from obtaining a male or female hormone panel, which will reveal whether someone has an imbalance in one or more of these hormones.

In summary, many people with hypothyroidism and hyperthyroidism experience memory loss and have difficulty concentrating. This is frequently true for those who are taking synthetic thyroid hormone or antithyroid medication, which of course are used to balance the thyroid hormone levels. So while balancing the thyroid hormone levels is of course important, and can help greatly with memory and concentration problems, it is also important to eat well, get sufficient sleep, and correct other hormone imbalances.

9 Ways to Improve Your Memory if You Have Hypothyroidism

Use reminders on your phone to keep you on schedule. iStock

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Forgetting where you left your keys, having a name slip from your mind, struggling to concentrate — these can all be part of frustrating brain fog or memory issues related to hypothyroidism.

Thyroid hormone regulates metabolism in every organ of the body, including the brain. When thyroid hormone is low, it can affect your memory span and ability to concentrate.

For many people, brain fog is a fleeting symptom. When hypothyroidism is diagnosed and treated early, metabolic processes normalize and you may not have a problem with memory issues or other symptoms hypothyroidism can cause, says Joel Zonszein, MD, an endocrinologist and director of the Clinical Diabetes Center at Montefiore Medical Center in New York.

But if you don’t take medication and continue to have a very low thyroid hormone level, you could end up with severe or persistent hypothyroidism, which can cause many changes in your body. In addition to weight gain, swelling, and vascular changes, your hypothyroidism symptoms can include cognitive problems. But these are extreme cases, Dr. Zonszein adds.

The good news: It’s very easy to test your thyroid hormone, and the tests are sensitive enough for your doctor to know if you’re taking the right amount of medication, he says. So talk to your doctor about possible symptoms of hypothyroidism, get tested, and get treated if necessary. “If we replace thyroid correctly, memory problems shouldn’t be a factor,” Zonszein says.

Tips to Improve Your Memory

Hypothyroidism that’s treated properly shouldn’t cause persistent brain fog or memory concerns. But anyone can experience issues with memory or concentration from time to time. These strategies can help:

Take your medication. The best thing you can do for your memory is to get your thyroid hormone back to a healthy level, and that means taking your medication regularly and correctly and going back to your doctor for follow-up appointments to be sure you’re taking the right dosage, Zonszein says. The American Thyroid Association says it’s best to take your thyroid hormone on an empty stomach at the same time every day, and to not stop taking it without first talking to your doctor.

Get out of the house, and get moving. Staying active has an important effect on the brain, so keep up with your hobbies and social activities, along with exercise. Physical activity is associated with a better working brain, according to the National Institute on Aging (NIA), which says that exercise has been found to stimulate your brain’s ability to maintain old network connections and make new ones. A study published in July 2019 in the Journal of the International Neuropsychological Society found that immediately following moderate exercise, participants showed a significant increase in memory.

Get a good night’s sleep. The deep sleep you get from a good night’s slumber helps keep your brain functioning well, Zonszein says. If you have trouble falling or staying asleep, try these tips:

  • Keep your bedroom dark and cool
  • Avoid alcohol, caffeine, and heavy meals too close to bedtime
  • Practice a relaxing bedtime ritual, like taking a warm bath, meditating, or reading a book you enjoy
  • Stick to a schedule: Go to sleep and wake up at the same time every day, even on the weekend

Play memory games. Anything that keeps your mind working, including computer games designed to make your brain sharper, is a good idea.

Focus on one thing at a time. Set your attention on only one thing, eliminate distractions like TV, and try not to let your mind drift to other things. When you focus like this, you’re more likely to be able to concentrate and remember what you’re doing, notes the American Psychological Association.

Stick to a schedule. When you do something at the same time every day and in the same sequence, it will be easier to remember.

Use tools to help you remember. If brain fog has you forgetting appointments, use tools like to-do lists, sticky notes, reminders on your phone, or a large wall calendar to help you stay on track, the NIA recommends.

Designate a place for your things. Keep your keys, wallet, purse, glasses, day calendar, and phone in the same place so you’re less likely to misplace them.

Repeat names and other important information. When you meet someone new or a doctor is giving you important information about your health, repeating the information back to the person or in your mind a few times can help you remember, Zonszein notes.

Thyroid problems can last a lifetime, so it means you’ll have to continue taking medication and seeing your doctor to ensure your levels stay healthy. But taking those steps to get treatment also means that memory issues related to hypothyroidism won’t last.

Neurological symptoms and signs in thyroid disease

Numerous complex regulatory mechanisms influence the development and function of the peripheral and central nervous system. Among them, hormones belong to the most potent regulatory factors. Various particles known for their hormonal activity serve as neurotransmitters. Additionally, hormones secreted systemically modulate the function of the nervous system both on the brain level and in peripheral organs. Thyroid function has been shown to play a crucial role in the proper cognitive development but also in many other aspects of nervous system activity, in mechanisms involving direct interaction with intrinsic regulatory circuits or indirectly by systemic effects exerted e.g. on the circulatory system or metabolic pathways. Due to these close relations with the nervous system function, disturbances of thyrometabolic state are associated with a vast spectrum of neurological signs and symptoms including: mood and cognitive disorders, headache, ophthalmoplegia, tremor and other movement disorders, muscle weakness etc. Both hyper- and hypothyroidism may cause psychiatric symptoms like depressive or anxiety disorder, memory deficits, executive inability and even psychosis. The severe decompensated hypothyroidism may result in myxoedema coma – a life-threatening condition with sequentially progressing encephalopathic symptoms. Steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAAT) represents another form of encephalopathic disorder associated with thyroid disease and causing potentially serious clinical complications. In the periphery, the thyrometabolic disturbances may affect muscle function resulting in subjective tiredness and low exercise tolerance and in some cases (especially in hypothyroidism) in objective myopathic signs. Also peripheral nervous system may be affected, mainly in hypothyroid patients, with greater tendency to develop peripheral polyneuropathy and entrapment neuropathies such as carpal tunnel or Guyone canal syndromes.

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Originally published on 29th April 2016 Last updated on 26th November 2019

Thyroid brain fog is real. Oh, it’s real alright. You can read the lighter side of my brain fog experiences here, but in this post, I’m going to explore how and why thyroid patients experience it among their many other symptoms.

What is Brain Fog?

Brain fog is often described as feelings of mental confusion or lack of mental clarity. The phrase comes from the feeling of a fog that reduces your ability to think clearly. It can feel like a mental block. It can cause a person to become forgetful, detached and discouraged and even depressed as a knock on effect.

Brain fog is a common symptom of thyroid problems, particularly hypothyroidism.

Read how thyroid patients commonly describe their brain fog here.

What Causes Thyroid Brain Fog?

Low Thyroid Hormone Levels

Thyroid hormones T3 and T4, used by the brain, have major influences over virtually every brain activity. So if a thyroid patient doesn’t have enough of these thyroid hormones in their body, brain fog often occurs, to varying degrees.

At times, mine was so severe that it seriously impacted my ability to work. I could read an email ten times and it still wasn’t registering in my mind.

Ensure that both your Free T3 and Free T4 are optimised and not just ‘normal’, ‘fine’ or ‘in range’.

Thyroid hormone, particularly T3, has an important role in the health and optimal functioning of your brain, including: cognitive function, the ability to concentrate, mood, memory and attention span. This explains why we can experience symptoms such as brain fog. T3 interacts with brain receptors and makes the brain more sensitive to chemicals such as serotonin and norepinephrine, which affects your alertness, memory, mood and emotion.


Inflammation in the body can mean all sorts of things, from a leaky gut, to gluten sensitivity and Hashimoto’s, and brain fog could be an indication of inflammation in the brain.

Dr Datis Kharrazian also comments on how Hashimoto’s, which around 90% of hypothyroid patients have , can cause inflammation in the brain, leading to symptoms like brain fog. I watched a seminar on this at the Healing Hashimoto’s summit, 13th-20th June 2016.

Being hypothyroid means you have a high chance of also having an autoimmune disease like Hashimoto’s, so cutting out gluten may also help with inflammation.

Mental Health

Since depression can also cause symptoms of brain fog, receiving adequate treatment for that and treating any underlying conditions is also important. Many thyroid patients are also on antidepressants. My depression was caused by an inadequately treated thyroid problem, so once my medication was right for me (switching to NDT), my depression lifted.

Vitamin Levels

Explore Vitamin B12, D, iron, ferritin etc. too to rule out other causes for brain fog and similar thyroid symptoms.

Some thyroid patients also swear by magnesium supplementation for improving brain fog.

Poor Gut Health

I experienced an impressive reduction in brain fog after overcoming candida (yeast overgrowth) and gut permeability with a functional medicine practitioner. With leaky gut, the intestinal barrier of the gut becomes permeable from hypothyroidism, infections, food intolerances (especially gluten) or even stress, allowing food particles to slip through and circulate round the rest of the body. This can lead to your microglia, who work to defend your central nervous system, going in to high alert – leading to inflammation in the brain.

Addressing any gut issues is crucial for overall thyroid health, and the first step many thyroid patients make to improve this is by removing offending foods from their dit, such as gluten and dairy, which alone can improve brain fog a lot.

A UK test for Candida can be found here. and a US test here.

Blood Sugar Imbalances

Symptoms of blood sugar issues can include headaches, feeling faint and dizzy, feeling hungry again quickly after eating, feeling tired, grouchy, irritable and foggy minded.

One of the simplest things you can do to improve any thyroid symptoms you have is to learn how to keep your blood sugar balanced. Since realising that I needed to adjust my diet to allow more protein and fat (and less sugar and carbs) in order to balance my blood sugar better, my low blood sugar bouts, irritable moods, groggy feeling, brain fog and slumps are gone.

Healthy fats play a big role in our mental health, mood and brain function. Good sources of fat include olive oil, sesame oil, avocados, olives, nuts, seeds, peanut butter, flaxseed, salmon, chia seeds, eggs and even seed butter.

I also ensure I consume enough protein with every meal and snack, in order to keep my blood sugar levels balanced; sources of protein can include meats, cheese, eggs, nuts, seeds, yoghurts, beans and legumes.

We should aim to eat every two to three hours to keep blood sugar levels balanced. Going long times without food, such as fasting, can place extra stress on the adrenal glands. Never skip meals.

What Helped Remove My Brain Fog

Going gluten-free dramatically improved my brain fog, but things like addressing low iron levels and low Vitamin D levels also helped. As well as addressing my gut health, diet and eating to better balance blood sugar levels.

Keep nudging your doctor for more reasons as to what is causing your brain fog if you still have no joy with any of the above tips. It’s often one of the most debilitating symptoms of being hypothyroid.

Do you experience thyroid brain fog?

See also:

The book Be Your Own Thyroid Advocate: When You’re Sick and Tired of Being Sick and Tired, which builds on this article in detail and covers the simple things you can do to resolve thyroid symptoms.

You can click on the hyperlinks in the above post to learn more and see references to information given, but more reading and references can also be found at:

If you found this article beneficial, please take a moment to share it so we can help others get better with hypothyroidism and Hashimoto’s, whilst also raising awareness. “Be Your Own Thyroid Advocate.” 2K Shares

Written by Rachel, The Invisible Hypothyroidism

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Rachel Hill is the highly ranked and award-winning thyroid patient advocate, writer, blogger, speaker and author behind The Invisible Hypothyroidism. She has two books: ‘Be Your Own Thyroid Advocate‘ and ‘You, Me and Hypothyroidism‘. Her thyroid advocacy work includes writing, speaking on podcasts and co-creating Thoughtful Thyroid courses. Rachel has worked with The National Academy of Hypothyroidism, BBC, The Mighty, Yahoo, MSN, ThyroidChange and more. She is well-recognised as a useful contributor to the thyroid community and has received eight 2019 WEGO Health Award Nominations.

What’s Causing Your Memory Loss?

A Harvard Health article

It’s Not Necessarily Alzheimer’s

More than 50 conditions can cause or mimic the symptoms of dementia, and a small percentage of dementias are reversible. Two common examples are dementia caused by vitamin B12 deficiency or an underactive thyroid (hypothyroidism). Getting the right diagnosis is important so that you know what options you have, because symptoms subside when the underlying problem is treated.

Distinguishing between types of dementia

For physicians and families intent on pinning down a diagnosis, one major complicating factor is the existence of so many kinds of dementia. More than 50 conditions can mimic or cause dementia.

Alzheimer’s disease is by far the most common intractable condition. But other causes of irreversible dementia include blood vessel diseasevascular dementia), other degenerative disorders (frontotemporal lobar degeneration, Parkinson’s disease, Huntington’s disease), slow-growing brain tumors, or infections of the central nervous system (Creutzfeldt-Jakob disease, AIDS dementia, neurosyphilis).

In some types of dementia, treatment will improve mental functioning, and in a small percentage, the dementia is completely reversible if treatment begins before permanent brain damage occurs. That’s why it is important to report to a doctor any signs of dementia as early as possible.

Reversible dementias

Reversible dementias are often easier to diagnose than irreversible dementias because they are usually accompanied by other, obvious symptoms. In the following conditions or situations, however, dementia may be the primary, or even the only, symptom. Proper treatment may improve or even restore cognitive functioning.


Delirium causes changes in mental functioning that can closely resemble dementia, but there are two important differences:

  • Speed of onset. The mental changes in delirium develop quickly, often in a matter of hours or days. In contrast, dementia evolves over months or years.
  • Level of consciousness. In delirium, consciousness is either clouded or fluctuates between drowsiness and alertness. Dementia doesn’t affect the level of consciousness.

Delirium is considered a medical emergency, in part because it’s often the main expression of a sudden, life-threatening illness. Elderly people are also susceptible to delirium after surgery.

Alcohol withdrawal syndrome presents the classic picture of delirium. Similarly, delirium can occur from abrupt withdrawal from benzodiazepines, a group of anti-anxiety drugs that includes diazepam (Valium), chlordiazepoxide (Librium), and alprazolam (Xanax).

Toxic reactions to drugs

Medications are common culprits in mental decline. With aging, the liver becomes less efficient at metabolizing drugs, and the kidneys eliminate them from the body more slowly. As a result, drugs tend to accumulate in the body. Elderly people in poor health and those taking several different medications are especially vulnerable.

The list of drugs that can cause dementia-like symptoms is long. It includes:

  • antidepressants
  • antihistamines
  • anti-Parkinson drugs
  • anti-anxiety medications
  • cardiovascular drugs
  • anticonvulsants
  • corticosteroids
  • narcotics
  • sedatives


People sometimes manifest dementia-like symptoms—forgetfulness, disorientation, inattentiveness, and slowed responses—when they are depressed. This so-called pseudodementia can masquerade as the depression that often accompanies Alzheimer’s disease, but there are subtle differences.

  • Pseudodementia. In pseudodementia, the depressed mood begins before there is any mental decline. Typically, the person complains about memory loss or lack of concentration, looks sad or worried, and speaks in a flat, expressionless tone.
  • Depression. In Alzheimer’s-related depression, the mental decline comes first, and the person usually tries to conceal memory problems, rather than call attention to them.

Vitamin B12 deficiency

In older people, the first symptoms of pernicious anemia are often confusion, slowness, irritability, and apathy. Other symptoms of pernicious anemia include:Dementia could be a symptom of pernicious anemia, a rare condition caused by low levels of vitamin B12. In people with pernicious anemia, the bone marrow produces red blood cells that are both larger and less numerous than normal (see illustration).

  • yellowish skin
  • fatigue
  • shortness of breath
  • headaches
  • numbness or tingling in the hands and feet
  • trouble keeping balance

Usually the B12 deficiency that underlies pernicious anemia is not caused by a lack of B12 in the diet. That’s because this vitamin is plentiful in eggs, dairy products, meat, fish, and poultry, and it’s efficiently stored in the liver.

Instead, a B12 deficiency usually occurs because an individual can’t absorb the vitamin from food. Fortunately, B12 injections, if started early, can remedy the deficiency and alleviate the symptoms of pernicious anemia.


Hydrocephalus (“water on the brain”) is an excess of cerebrospinal fluid around the brain. The fluid is secreted by the ventricles (cavities in the center of the brain). It circulates around the spinal cord and is absorbed by veins on the external surface of the brain.

Congenital hydrocephalus is usually diagnosed shortly after birth, but normal-pressure hydrocephalus occurs in a small number of elderly people. This condition can result from head trauma, brain hemorrhage, or meningitis (inflammation of the membrane covering the brain), but most cases occur spontaneously without an obvious preceding illness.

In addition to developing dementia, people with this condition lose bladder control and walk in a slow, hesitant manner, as if their feet are stuck to the floor. A surgically implanted tube (shunt) that drains fluid from a cavity in the brain (the lateral ventricle) to the jugular vein or to the abdomen brings rapid improvement, provided treatment is started soon after the symptoms appear.


Brain tumors may be malignant (cancerous) and therefore capable of invading surrounding tissue. Or they may be benign (self-contained).

Brain tumors can interfere with cognitive functioning and cause personality changes. Depending on their location, they can trigger other symptoms, such as headaches, seizures, or vomiting.

The first symptoms of slow-growing tumors frequently resemble dementia, especially in older people.

Subdural hematomas

Hematomas are blood clots caused by bruising. When they are located in the subdural area, between the brain surface and the thin membrane that covers it (the dura), they can cause symptoms that mimic Alzheimer’s disease. Such subdural hematomas can also be life-threatening, causing coma and death.

Most subdural hematomas are caused by severe head trauma sustained in automobile crashes.

But elderly people sometimes develop subdural hematomas after a very minor (and, therefore, often forgotten) head injury. As blood oozes into a closed space, the hematoma enlarges and begins to interfere with brain function.

Removing the clot within weeks of the injury may restore mental function. However, the symptoms often evolve so slowly that diagnosis is delayed for months.

Thyroid disease

An overproduction of thyroid hormones (hyperthyroidism) is commonly caused by Graves’ disease, while an underproduction (hypothyroidism) usually results from Hashimoto’s thyroiditis. Both disorders can cause dementia-like symptoms.

  • Hyperthyroidism. To diagnose hyperthyroidism, physicians use a simple blood test that measures levels of thyroid hormones. Surgically removing the thyroid or destroying it with radioactive iodine usually corrects the cognitive problems.
  • Hypothyroidism. This is diagnosed by measuring the level of thyroid-stimulating hormone circulating in the blood. Physicians usually recommend thyroid hormone replacement, but this treatment doesn’t always reverse the dementia.


Wernicke-Korsakoff syndrome, an irreversible state of confusion and amnesia in alcoholics, results from thiamine deficiency due to long-term malnutrition. But consuming excessive amounts of alcohol for a decade or more can also cause impaired thinking that resembles Alzheimer’s disease.

In dementia due to alcoholism, memory, orientation, and attention deteriorate, although verbal skills are not always severely affected. In this type of dementia, abstinence may partly restore mental functioning.

Irreversible dementias

Although there are many causes of irreversible dementia, the following conditions are among the most common. In some cases, prompt treatment can prevent further damage, but lost cognitive functioning cannot be restored.

Alzheimer’s disease

Alzheimer’s is distinguished from other dementias at autopsy by the presence of sticky beta-amyloid plaques outside brain cells (neurons) and fibrillary tangles within neurons. Although such lesions may be present in any aging brain, in people with Alzheimer’s these lesions tend to be more numerous and accumulate in areas of the brain involved in learning and memory.

The leading theory is that the damage to the brain results from inflammation and other biological changes that cause synaptic loss and malfunction, disrupting communication between brain cells. Eventually the brain cells die, causing tissue loss (see illustration). In imaging scans, brain shrinkage is usually first noticeable in the hippocampus, which plays a central role in memory function.

The hallmark symptom of Alzheimer’s is difficulty in recalling new information. As Alzheimer’s progresses, the following may occur:

  • Memory loss. This may be severe enough to disrupt daily life (for example, the person may get lost in a previously familiar neighborhood).
  • Cognitive decline. The individual may also experience decline in cognitive ability (finding it hard to make decisions, solve problems, or make good judgments).
  • Mood or personality changes. An individual with Alzheimer’s may undergo significant changes in mood and personality (such as becoming more irritable, hostile, or apathetic).

Alzheimer’s is severely debilitating, and death usually occurs within three to nine years after it is diagnosed. Five drugs have been approved for treating Alzheimer’s, but they alleviate symptoms only slightly.

Vascular dementia

Some cognitive problems stem from insufficient blood flow to portions of the brain. The decrease in blood flow is often the result of atherosclerosis (the accumulation of fatty deposits on artery walls) in the blood vessels that feed the brain. The resulting interruption of blood flow creates areas of dead tissue.

These events—which are in fact tiny strokes—often go unnoticed, because each one damages just a small part of the brain and doesn’t cause long-term impairment. But the cumulative damage can lead eventually to large areas of dead brain tissue, and symptoms such as confusion, impaired thinking, slurred speech, and paralysis may arise.

People with vascular dementia usually have one or more of the following risk factors:

  • hypertension (high blood pressure)
  • cardiovascular disease
  • diabetes
  • a history of stroke

The classic symptom of vascular dementia is an abrupt mental change, sometimes accompanied by paralysis or slurred speech. The mental deterioration proceeds in a “stairstep” pattern—a person suffers a sudden cognitive decline, the decline levels off, and then new strokes cause another sudden decline.

Degenerative diseases

Most dementias are caused by degenerative diseases, conditions whose deterioration cannot be stopped. Alzheimer’s disease is the degenerative disease that is most often responsible for dementia, accounting for more than 50% of cases. Frontotemporal lobar degeneration, Parkinson’s disease, and Huntington’s disease account for approximately 25% of all dementias.

Frontotemporal lobar degeneration. This group of diseases, formerly called Pick’s disease, is characterized by atrophy of the front part of the brain, including the frontal and temporal lobes. It is often confused with Alzheimer’s disease because the symptoms are sometimes identical. Some experts believe it may be the second most common dementia, after Alzheimer’s disease.

The cause of frontotemporal lobar degeneration is unknown, but some variants can run in families, and it is sometimes associated with gene mutations. People with frontotemporal lobar degeneration exhibit symptoms such as:

  • prominent aphasia (impaired ability to use language) early in the illness
  • loss of inhibition, resulting in sociopathic or hypersexual behavior
  • loss of emotional responses such as fear
  • compulsively putting objects in their mouths.

Parkinson’s disease. This is a movement disorder resulting from a deficiency of dopamine, a neurotransmitter involved in coordinating muscle activity as well as memory function.

Its hallmarks include tremors, rigid limbs, and difficulty starting or stopping movement. Mild cognitive problems are common early in the disease, and dementia occurs in 30% to 80% of Parkinson’s patients in the late stages.

Some people with Parkinson’s disease develop dementia because they also have Alzheimer’s disease. In other cases, the dementia is associated with hallucinations and appears to be linked to damage in the limbic and cortical areas of the brain. This variant of Parkinson’s is called Lewy body dementia.

Drugs that increase dopamine transmission, such as levodopa (Sinemet), help control the physical symptoms of Parkinson’s but don’t improve mental function.

Huntington’s disease. Huntington’s disease is a rare inherited disorder linked to an abnormal gene on chromosome 4. Its symptoms include involuntary writhing movements and dementia, and they often begin between the ages of 20 and 40.

Mental disturbances may occur before or after physical problems appear, and people are often difficult to care for because of their irritability, aggressiveness, and erratic behavior. Medications can control the movement and mood disorders, but they don’t stop the disease from progressing.

Infectious dementias

Virtually any infectious agent that attacks the central nervous system can cause dementia.

Creutzfeldt-Jakob disease. This is a rare, rapidly progressive dementia caused by a type of infectious agent called a prion. The initial symptoms are fatigue and subtle changes in behavior. Typically, the disease progresses to movement problems, seizures, coma, and—within a year—death.

AIDS dementia. This form of dementia occurs in people with AIDS. The dementia can develop rapidly, sometimes in a matter of weeks, and consists of forgetfulness, inattentiveness, and thinking difficulties.

Neurosyphilis. Before the introduction of penicillin, up to 30% of dementia patients admitted to mental institutions had neurosyphilis. This disorder, which develops about 15 years after syphilis infection, is now rare, because syphilis is typically treated before it reaches that point.

Adapted with permission from Alzheimer’s Disease: A guide to diagnosis, treatment, and caregiving, a special health report published by Harvard Health Publishing.

Are You Living Life with Thyroid Brain Fog?

Could brain fog be a warning sign your thyroid is NOT optimally treated?

It’s critical you find out.

Poorly managed hypothyroidism can have a powerful effect on your brain.

Written by Hugh Melnick, MD, F.A.C.O.G.

At one time or another, everyone has suffered from what they would describe as brain fog. The following factors can bring with them a decreased sense of neurological function:

  • Stress
  • Pregnancy
  • Sleep deprivation
  • Illness

Let’s focus on the last item and find out more about how brain fog relates to hypothyroidism.

Critical Mood Deterioration

These three words are how medical experts and research analysts describe the mentally foggy state that many thyroid patients find themselves in. In fact, current studies indicate that an underactive thyroid can take a significant toll on your mental health.

There’s more to hypothyroidism than the physical symptoms we’ve all learned to watch for. The fact of the matter is that over time, a thyroid gland that produces less hormone than it should will affect your neurological function.

Why? Because the hormone deficiency slows everything down, including neurological functions.

This domino effect can leave you with a chemical imbalance that includes symptoms like:

  • Inability to concentrate
  • Detachment from personal relationships and activities
  • Low self-esteem
  • Depression
  • Inability to connect details
  • Short-term memory problems
  • Slowed mental reactions
  • Confusion

As your undiagnosed symptoms worsen, your quality of life also decreases.

Temporary Fog or Something Else?

Brain fog has many causes and thyroid problems are definitely on the list. Anything that causes a misfire in your neurotransmitters can lead to a feeling of forgetfulness or living in a mental fog. But it’s very important to realize when these symptoms might be indicating that you have a serious health problem.

Stress or even trouble sleeping can trigger temporary brain fog. We’ve all been in situations where feeling emotionally overwhelmed or tired leaves us also feeling mentally slower than usual.

The question we need to ask ourselves is: when might it be something more serious? Brain fog can actually signal the onset of disorders and processes in the body that need to be managed and addressed such as:

  • Thyroid Problems
  • Adrenal Failure
  • Menopause

Living Life in a Thyroid Brain Fog

Unfortunately, the neurological symptoms that about 5% of all hypothyroidism patients suffer from are largely underestimated or outright ignored by a lot of practicing medical professionals.

This is not something that can simply be treated with complimentary drug therapy. It takes more than antidepressants to really understand and address this problem – it takes looking at thyroid function as a whole.

Patients often complain that even though they are in treatment for their thyroid condition, they don’t feel better physically or mentally.

Many doctors write this off as a casualty of the adjustment process, but if they look closer, and pay attention a little sooner, these mental changes could be an effective early warning sign of an underlying thyroid condition.

Thyroid conditions are notoriously difficult to diagnose in the early stages. The standard blood tests aren’t accurate and it’s easy to confuse the symptom presentation with other health problems. Search until you find a doctor who will listen.

The Thyroid

The thyroid gland is a small, butterfly shaped mass of tissue found in the neck, just below the “Adam’s Apple.” Despite its small size, it has a critical role in determining how our bodies function, and, ultimately, how well we feel.The thyroid controls the body’s metabolism, which is the energy supply that is essential for all bodily functions. Think of the thyroid gland as an automobile’s fuel pump. If the pump is not working up to capacity, the car’s engine will not get enough fuel, and will run slowly and inefficiently. Should the pump supply too much fuel to the engine, it will run too fast and eventually burn out. An underactive thyroid gland causes a medical condition known as hypothyroidism.

For some unknown reason, it occurs much more frequently in women than in men, and as many as 15% of the female population may have some degree of thyroid under activity.

Thyroid Symptoms

The symptoms of hypothyroidism are quite common and diverse. They affect the way a woman looks and feels, both physically and emotionally. Without any doubt, an untreated under active thyroid gland can have a profoundly negative effect upon a woman’s quality of life.

Having seen the wide spectrum of symptoms associated with hypothyroidism, it is apparent that they are extremely common complaints, experienced by many women. It is quite possible that either you, one of your friends or a family member is plagued by one or more of these troublesome symptoms. Many times, women with these complaints have been tested for hypothyroidism and were told that, despite their symptoms, they did not have an under active thyroid gland because their thyroid blood test results were within the “normal” range. They may have been told that their symptoms are part of the “normal” aging process or are caused by anxiety or depression. In many instances, they are referred to a psychiatrist for treatment with antidepressants and psychotherapy, but often these treatments may not make a symptomatic woman feel better.

A Common Thread of Progression

Rather than list all possible symptoms of hypothyroidism; I’ve chosen to list one of the most common symptomatic progressions. This is the typical presentation most patients go through:

  • Most symptoms, such as lower heart rate, tiredness, poor memory or difficulty in thinking, and even constipation, are due to inadequate stimulation of the various organs in the body due to insufficient amounts of thyroid hormone.
  • Other symptoms, such as inability to tolerate cold environments, are directly due to the decrease in heat generated within the body by slowed metabolic activity.

Most people with hypothyroidism will experience some of the following symptoms:

  • Slow heart rate
  • Tiredness
  • Inability to tolerate cold
  • Weight gain
  • Emotional depression
  • Drowsiness, even after sleeping through the night
  • Heavy or irregular menstrual periods (in premenopausal women)
  • Muscle cramps
  • Constipation

Later symptoms of hypothyroidism include:

  • Dry, flaky skin
  • Hair loss
  • Impaired memory and difficulty in thinking
  • A deepening voice
  • A numb sensation in the arms and legs
  • Puffiness in the face, especially around the eyes (a condition called myxedema, which is an indication that the disease has become serious)

Subclinical Hypothyroidism

Such symptomatic individuals may actually have a condition known as Subclinical Hypothyroidism. In this clinical condition, a patient may be symptomatically hypothyroid, yet her blood tests may suggest, but not fully support, the diagnosis of thyroid gland under activity. In subclinical hypothyroidism, there is a partial decrease in the thyroid glands ability to produce enough hormones to make the body’s metabolism work at 100% efficiency; hence an individual will be symptomatic. Such individuals may benefit from a therapeutic trial of treatment with a natural prescription thyroid supplement.

There are two basic problems that account for the failure to diagnose many cases of subclinical hypothyroidism. First is that what is considered to be the “normal range” for one of the main blood tests used to diagnose hypothyroidism (TSH-Thyroid Stimulating Hormone) is too broad to diagnose many patients who are symptomatically hypothyroid. In addition to TSH levels, the amount of other thyroid hormones such as T4 and T3, as well as antibodies against thyroid tissue, must be evaluated in any woman having symptoms associated with hypothyroidism.

The second difficulty in diagnosing hypothyroidism is that we, as physicians and scientists, are trained to rely more on objective findings, such as laboratory tests, than subjective factors, such as a patient’s symptoms. Unfortunately, many doctors will not feel comfortable making a diagnosis of hypothyroidism if a patient’s blood tests fall anywhere within what is strictly defined as the normal range, even if such levels may be close to indicating the possibility of an under-active thyroid gland in a symptomatic patient. There are definite “gray zones” that exist clinically; such that a patient’s clinical symptoms may not be completely documented by their laboratory results.

It is important to remember that blood tests only reflect a “moment in time” in the human body and consequently may not always accurately represent its true condition! Therefore, a patient’s symptoms must be considered as being of equal significance as their blood test results in diagnosing hypothyroidism.

In my experience, many women who present with physical and psychological symptoms associated with hypothyroidism will have some degree of improvement when treated with supplemental thyroid medication.

Improvement should be noted in two to eight weeks. Increases in energy levels, sex drive, body temperature and memory are the first changes noted. Water retention also improves fairly rapidly. An increased feeling of well-being may also be noticed, as depression resolves.

Hair and skin begin to improve after 4-6 weeks, but weight loss usually will take quite a bit longer since the body takes time to breakdown existing fatty deposits. When I treat women who have symptoms associated with hypothyroidism, I initially use a natural desiccated thyroid medication (NDT) that has been available since the 1940’s, such as the brand Armour Thyroid Extract U.S.P. It is a combination of two active forms of thyroid hormone, T3 and T4. T4 is the form of the thyroid hormone that is in the synthetic thyroid medications commonly prescribed today. Normally, T4 is converted into T3, which is the biologically active form of the thyroid hormone that actually controls the body’s metabolism. In a significant number of individuals, the body is unable to properly convert T4 into T3. Hence a patient may be clinically hypothyroid, yet have “normal” blood tests. Therefore, I find that a woman’s clinical response to the natural form of a combination of T3 and T4, will often be better than giving T4 alone.

It is of critical importance that a physician be finely attuned to a patient’s symptoms and her symptomatic response to treatment. Thyroid supplement therapy is very individualized, since the dosage requirements are quite different for each patient. A patient’s dosage needs to be reevaluated based upon the degree of symptomatic improvement and “finetuned” as necessary.

The important point to remember is that the evaluation of symptoms is of equal significance to the levels of thyroid hormone in the blood.


The diversity of symptoms can make the diagnosis and treatment of hypothyroidism quite challenging, especially since laboratory tests do not always reflect thyroid gland under activity in a significant number of symptomatic individuals.

If you, a friend, or a loved one experience any of the above symptoms or generally feel poorly, you should speak to your doctor about the possibility that subclinical hypothyroidism may be the cause of such symptoms. After an appropriate diagnostic evaluation of symptoms and laboratory tests, a therapeutic trial of a natural thyroid supplement or any other thyroid medication may provide relief from these troubling symptoms.

Thyroid conditions are notoriously difficult to diagnose and treat optimally. Search until you find a doctor that will listen.

About Hugh Melnick, MD, F.A.C.O.G.

Dr. Hugh D. Melnick is a reproductive endocrinologist who has been treating patients with hormonal and fertility problems since 1976. In 1983, Dr. Melnick founded Advanced Fertility Services, which was the first free standing In Vitro Fertilization Center in New York City and is still its medical director. He has been impressed by the large number of infertile women that he has seen over the years, who are symptomatically hypothyroid, and who conceive after treatment with thyroid medication. Dr. Melnick is one of the incredible experts I interviewed for my book Your Healthy Pregnancy with Thyroid Disease: A Guide to Fertility, Pregnancy, and Postpartum Wellness.

Dr. Melnick’s vast clinical experience together with his own personal experience having hypothyroidism has enabled him to develop a unique approach to the diagnosis and treatment of hypothyroidism. During his many years of clinical practice, he has recognized how hypothyroidism can adversely affect every part of the human body, creating many unpleasant symptoms, which inevitably interfere with a productive and enjoyable quality of life. In addition to his fertility services, he works with thyroid patients at


READ NEXT: Why are there so many unhappy thyroid patients?

We all forget things from time to time. In fact, some memory loss is natural when we’re under stress, depressed, going through a major life change, or as we grow older. As we age though, in particular, we pay more attention to our forgetfulness than we did when we were younger.

Forgetting something isn’t usually a major problem. It’s an occurrence that we often laugh about, but when we start to forget things more frequently, that’s when concern generally sets in. If the memory loss continues and our concentration also seems to wane, that concern often turns to panic. Fearing the problem is serious and could lead to permanent impairment, some people even ignore the issue, not wanting to think about a possible grave future.

However, many treatable medical conditions can cause memory problems as well as a general decline in cognitive function. One gland, in particular — when not functioning correctly — can lead to memory loss and/or brain fog.

That gland is the thyroid.

The thyroid, shaped like a butterfly and in the anterior of the neck, controls hormones and regulates metabolic functions, turning nutrients into energy. The brain requires adequate levels of thyroid hormones to function properly. When there’s an imbalance, problems arise. Your thyroid can cause memory problems that actually mimic the symptoms of mild dementia. Those most at risk to develop thyroid issues are older women, those with a family history of thyroid disease, and people who smoke.

The two types of thyroid problems that we commonly hear about are:

Hypothyroidism – This disorder is the UNDER-production of thyroid hormones. It can affect verbal memory and make it more difficult to concentrate, among other problems.

Hyperthyroidism – This disorder is the OVER-production of thyroid hormones. It can speed up thinking and metabolism, but can affect the ability to focus, making tasks more difficult.

Thyroid dysfunction of either kind interferes with our body’s neurotransmitter systems, which communicates information between our brain and our body. This can cause all sorts of physical and
cognitive issues.

If your thyroid is your problem, you’re not alone. Millions of people worldwide suffer from thyroid problems. The exact numbers aren’t known because the condition goes undetected in so many people. Even though the older you get, the more likely you’ll develop a thyroid disorder, younger people can also develop thyroid disease. Fortunately, these problems are most often treatable with medication or surgery. Supplements and eating healthy can also help support proper thyroid cell metabolism.

Once treated, and thyroid levels return to adequate ranges, cognitive function most often improves, leaving no permanent defects. Significantly older patients may not show as much improvement, but they can still benefit from treatment to stop any decline they’re suffering from getting worse.

Thyroid treatment and its relationship to cognitive function, as well as whether treatment can “completely” reverse one’s memory problems has been a subject of debate over the years. But according to the European Journal of Endocrinology‘s clinical report on the results of the Rancho Bernardo study — which followed several hundred older adults treated for hypothyroidism over numerous years — comparing the thyroid and cognitive function, “Long-term treated hypothyroidism is not associated with impaired CF or depressed mood in old age. The lack of association with CF is reassuring with regard to long-term use of thyroid hormone therapy.”

If you’re experiencing forgetfulness beyond what you feel is normal and/or you’re having a harder time focusing than usual, don’t assume the worst and just live with it. Get tested for thyroid problems. If diagnosed with an issue, medication could solve your memory problems and get you back to your old self again, more quickly than you realize.

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