What does thyroid brain fog feels like?

Inside: Thyroid problems are said to cause brain fog in many people. But, how do you know if you actually are having a brain fog that is associated with Thyroid issues? Know more here.

“Brain fog,” also known as “mental fog,” “reduced awareness,” or “cognitive impairment,” is an informal term for a range of cognitive symptoms, including:

  • Decreased mental clarity and cognitive function
  • Difficulty concentrating and multitasking
  • Loss of short-term and long-term memory
  • Slow thinking
  • Confusion
  • Malaise

Because these symptoms are generally subjective, doctors may consider them too mild or nonspecific to diagnose cognitive impairment.

brain fog

There are many possible causes of "brain fog," but some scientists believe that almost all inflammation and free radicals originate in the limbic system, the brain region responsible for emotional, cognitive, and executive functions. I think it does damage.

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Factors Causing Brain Fog

Factors and conditions that can cause "brain fog" include:

  • Anxiety and stress
  • depression
  • Sleeping disorder
  • Hormonal imbalance
  • Infection
  • Toxin
  • diet
  • Drugs and drugs conditions such as multiple sclerosis, lupus, and fibromyalgia


Does hypothyroidism trigger brain fog?

People with undiagnosed or undertreated hypothyroidism often complain of forgetfulness, difficulty finding the right words, and lack of attention. But does this mean hypothyroidism triggers "brain fog"? 

In any case, keep in mind that the relationships between different types of hypothyroidism and symptoms of brain fog have been studied primarily in cohort studies. These studies can tie the condition to specific symptoms, but cannot pinpoint the cause of those symptoms.

"Brain fog" is an informal term for a constellation of symptoms that include decreased mental clarity, memory problems, difficulty concentrating, slow thinking, and fatigue. It can be caused by many things, including anxiety, certain medications, and autoimmune diseases.

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Overt hypothyroidism

The condition is associated with several "brain fog" symptoms, especially in older adults, according to six observational studies involving more than 200 people. However, some studies have also reported the following issues:

  • General Intelligence
  • Note
  • Ability to learn
  • Visual-spatial skills
  • Adjustment

Symptoms can generally be reversed with thyroid replacement therapy, even in the most severe cases.


However, in some individuals, cognitive symptoms may persist. For example, a study of over 100 people found that they had memory and attention deficits even after 5.5 years of this therapy.

Untreated hypothyroidism can lead to dementia in adults and irreversible brain damage in children with congenital hypothyroidism.

Overt hypothyroidism is associated with "brain fog" symptoms in the elderly. Thyroid replacement therapy generally reversed cognitive symptoms


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Subclinical hypothyroidism

Cases of subclinical hypothyroidism are more controversial and less conclusive. The most common symptom is memory loss, with some studies reporting sluggish thinking, decreased alertness, and fatigue.

A meta-analysis found insufficient or weak evidence linking subclinical hypothyroidism with cognitive impairment. In general, the most severe cases (those with the highest TSH levels) were most likely to develop symptoms.

Subclinical hypothyroidism rarely requires treatment. In the most severe cases, thyroid hormone replacement can improve symptoms.

Researchers disagree about whether subclinical hypothyroidism can cause "brain fog" symptoms.


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Hashimoto’s encephalopathy

Hashimoto's thyroiditis is an autoimmune disease in which the immune system produces antibodies that target and progressively damage the thyroid gland. This causes hypothyroidism, manifesting itself as "brain fog."


Or there is a rare type of autoimmune brain disease that causes stroke-like attacks or damages the brain over time. Although its association with Hashimoto's thyroiditis remains unclear, the condition is called Hashimoto's encephalopathy because it is also associated with high levels of antibodies to the thyroid gland.

In addition to seizures, psychosis, and behavioral changes, Hashimoto's encephalopathy can cause progressive "brain fog" symptoms such as:

  • Slow thinking
  • Difficulty concentrating
  • Executive dysfunction
  • Amnesia
  • Disorientation and confusion
  • Speech impediment

Brain imaging studies of people with this condition show mixed results. Some brains were normal in appearance; others showed changes in white matter, reduced blood supply, swelling, and damage.

Some scientists believe that thyroid antibodies can damage the brain (including myelin) or cause inflammation in blood vessels in the brain.

Hashimoto's thyroiditis can cause "brain fog" symptoms. If left untreated, this condition can lead to sluggish thinking, difficulty concentrating, memory loss, and speech problems.

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Resistance to thyroid hormone

Thyroid hormone resistance is a condition in which TSH levels remain elevated despite normal to elevated thyroid hormone levels. This condition is due to mutations in thyroid hormone receptors.

Although "brain fog" usually doesn't present itself, many people have ADHD or a below-average IQ, so thyroid replacement therapy can help.

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Hypothyroidism and Health Risks

Several studies have linked hypothyroidism with the increased prevalence of certain diseases. Keep in mind, however, that just because hypothyroidism is associated with a disease doesn't necessarily mean that everyone with hypothyroidism actually develops the disease! Environmental factors can influence risk.


A study of 70 individuals with a family history of Alzheimer's disease found a high prevalence of autoimmune hypothyroidism (41%), suggesting that genes responsible for both conditions may be inherited together. Something has been suggested.


The association between subclinical hypothyroidism and Alzheimer's disease is weak or non-existent. 

Three other included studies found no association between the two conditions. Similarly, subclinical hypothyroidism, unlike hyperthyroidism, was not associated with an increased risk of dementia in two studies involving more than 12,000 people.

Conversely, another study of over 650 people associated this condition with an increased risk of brain damage (vascular dementia) due to reduced blood supply.

The impact of the history of thyroid replacement therapy is also unknown. One of his studies of about 500 people was associated with an increased risk of Alzheimer's disease, but another study of more than 2,500 people did not.

Some researchers have suggested that certain types of dementia may be linked to autoimmune hypothyroidism, but the evidence is mixed. 

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Heart and blood vessel disease

Subclinical hypothyroidism was associated with an increased risk of heart disease (heart attack, congestive heart failure, arrhythmia, etc.) in four of his studies involving more than 9,000 people.

Similarly, in a study of more than 27,000 people, high blood cholesterol, arterial blockages, and stroke were more common in those who had a history of thyroid replacement therapy.


Hypothyroidism is a condition in which the thyroid gland does not produce enough thyroid hormone. "Brain fog" is not a medical condition, but a term that refers to a set of symptoms that can affect cognition, mood, and energy.

Hypothyroidism can have many different causes, but it can present itself as a “brain fog” symptom. Most people suffer from forgetfulness, poor concentration, and learning disabilities. Some researchers believe that oxidative stress and inflammation play a role in these symptoms.


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