Primary Hypothyroidism: Symptoms, Causes, Diagnosis, Treatment and Prevention

It is a disease caused by an alteration in the functioning of the thyroid gland that can affect all bodily functions.

It is the opposite of hyperthyroidism, where the thyroid produces too much hormone. However, the link between hyperthyroidism and hypothyroidism is complex, and one can lead to the other in certain circumstances.

Thyroid hormones regulate metabolism or the way the body uses energy. If thyroxine levels are low, many of the body’s functions decrease. About 4.6 percent of the population 12 years old or older in the United States has hypothyroidism.

The thyroid gland is located in the front of the neck, below the larynx or voice box, and has two lobes, one on each side of the trachea.

It is an endocrine gland composed of special cells that produce hormones. Hormones are chemical messengers that transmit information to the organs and tissues of the body, controlling processes such as metabolism, growth, and mood.

The production of thyroid hormones is regulated by the thyroid-stimulating hormone (TSH) produced by the pituitary gland. This, in turn, is regulated by the hypothalamus, a region of the brain. TSH ensures that enough thyroid hormones are produced to meet the body’s needs.


Primary hypothyroidism refers to the underproduction of hormones in the thyroid gland. It has a wide range of symptoms. Thyroid hormones affect the systems of multiple organs, so the symptoms of hypothyroidism are varied and wide-ranging.


The thyroid creates two thyroid hormones, triiodothyronine (T3) and thyroxine (T4). These regulate the metabolism and also affect the following functions:

  • Brain development
  • Breathing.
  • Parts of the heart and nervous system.
  • Body temperature.
  • Muscular strength.
  • Dry skin.
  • Menstrual cycles
  • Weight.
  • Levels of cholesterol.

The symptoms of primary hypothyroidism commonly include, but are not limited to:

  • Fatigue.
  • Weight gain.
  • Intolerance to the cold.
  • Decreased heart rate, movements, and speech.
  • Pain in the joints and muscles, cramps, and weakness.
  • Constipation .
  • Dry Skin.
  • Hair and nails are thin and brittle.
  • Decreased sweating
  • Tingle.
  • Abundant periods or menorrhagia.
  • Weakness.
  • High cholesterol.
  • Swollen face, feet, and hands.
  • Insomnia .
  • Balance and coordination.
  • Loss of libido
  • Recurrent urinary and respiratory infections.
  • Anemia.

If left untreated, the following symptoms may manifest:

  • Hoarseness
  • Swelling in the face
  • Eyebrows thinned or missing.
  • Slow heart rate
  • Hearing loss.

If it develops in children or adolescents, the signs and symptoms are generally the same as in adults.

However, you may also experience:

  • Poor growth
  • Delay in the development of teeth.
  • Poor mental development
  • Delayed puberty.

Hypothyroidism develops slowly. The symptoms may go unnoticed for a long time and maybe vague and general.

Symptoms vary widely among individuals and are shared by other conditions. The only way to obtain a specific diagnosis is through a blood test.


Primary hypothyroidism can occur if the thyroid gland does not function correctly or if the hypothalamus or pituitary gland does not adequately stimulate the thyroid gland.

Hashimoto’s disease:

The most common cause of hypothyroidism in the US UU is Hashimoto’s disease, also known as chronic lymphocytic thyroiditis or autoimmune thyroiditis.

Hashimoto’s disease is an autoimmune disease, a disorder in which the immune system attacks the body’s cells and organs.

The condition causes the immune system to attack the thyroid gland, which causes inflammation and interferes with its ability to produce thyroid hormones.


Thyroiditis is an inflammation of the thyroid gland. It causes the thyroid hormones to leak into the blood, raising its overall levels and leading to hyperthyroidism. After 1 to 2 months, this can turn into hypothyroidism.

Thyroiditis can be caused by a viral or bacterial infection, an autoimmune condition, or after pregnancy.

Congenital hypothyroidism:

In cases of congenital hypothyroidism, the thyroid gland does not function properly from birth.

This can lead to physical and mental growth problems, but early treatment can prevent these complications. The majority of newborns in the US UU undergo screening for hypothyroidism.

Hypothyroidism after thyroid surgery:

Primary hypothyroidism may occur after part of the thyroid is removed during surgery.

Several conditions such as hyperthyroidism, goiters, thyroid nodules, and thyroid cancer can be treated by partial or total thyroid gland removal. This can cause hypothyroidism.

Treatment with thyroid radiation can also cause hypothyroidism. Radioactive iodine is a standard treatment for hyperthyroidism. It works by destroying the cells of the thyroid gland and by decreasing the production of T4.

Radiation is also used to treat people with head and neck cancer, Hodgkin’s disease, and other lymphomas, which can cause damage to the thyroid gland.

Abnormalities of the pituitary gland:

If the pituitary gland fails to function correctly, the thyroid gland may not produce the correct amount of thyroid hormone. Pituitary tumors or pituitary surgery can affect the pituitary gland’s function, which can adversely affect the thyroid gland.

Sheehan syndrome is a condition involving damage to the pituitary gland. Suppose a woman loses a life-threatening amount of blood or has external blood pressure during or after delivery. In that case, the gland can be damaged and cause an insufficient production of pituitary hormones.

Iodine imbalance:

Iodine is necessary for producing thyroid hormones, but the level must be balanced. Too much or too little iodine can cause hypothyroidism or hyperthyroidism.


Doctors usually perform a physical examination, take a medical history and send it to a laboratory for analysis. The most common blood test is the TSH test. This detects the amounts of TSH in the blood.

If the TSH reading is higher than usual, the patient may have hypothyroidism. If the TSH levels are lower than usual, the patient may have hyperthyroidism or hypothyroidism.

The autoantibody tests against T3, T4, and thyroid are additional blood tests used to confirm the diagnosis or determine its cause.

The doctor can perform a complete thyroid panel and evaluate the levels of T3 and T4, TSH, and thyroid autoantibodies to fully establish the health and activity of the thyroid gland. There may also be tests to monitor cholesterol levels, liver enzymes, prolactin, and sodium.


The dosage is determined by the history of the patient, the symptoms, and the current level of TSH.

Doctors will regularly check the patient’s blood to determine if the dose of synthetic T4 should be adjusted.

Regular monitoring will be required, but the frequency of blood tests will likely decrease over time.

Iodine and nutrition:

Iodine is an essential mineral for thyroid function. Iodine deficiency is one of the most common causes of goiter development or abnormal thyroid gland enlargement.

Maintaining adequate iodine intake is essential for most people. Still, those with autoimmune thyroid disease may be particularly sensitive to the effects of iodine, which means it can trigger or worsen hypothyroidism.

People with hypothyroidism should discuss any significant changes in their diet with their doctor, especially when starting a high-fiber diet or eating a lot of soy or cruciferous vegetables.

Diet can affect the way the body absorbs thyroid medication. During pregnancy, iodine requirements increase. Using iodized salt in the diet and taking prenatal vitamins can maintain the required iodine levels.

Hypothyroidism can usually be managed appropriately on the advice of a qualified health professional.

With proper treatment, thyroid hormone levels should return to normal. In most cases, medications for hypothyroidism should be taken for the rest of the patient’s life.

Natural medicine:

Some natural remedies for primary hypothyroidism are proposed, but it is essential to first talk to a doctor because the treatment of thyroid problems should be balanced delicately.

Selenium: people with some types of thyroid problems may benefit from taking selenium, but this should only be used after reviewing with a doctor. The researchers noted that “deficiency or excess of this micronutrient may be associated with adverse outcomes.”

Selenium supplements that a health professional does not recommend can be dangerous.

Vitamin D: A deficiency has been linked to hypothyroidism. Supplementation may be necessary to achieve the benefits of vitamin D in the blood above 50 ng / dL.

Probiotics: Some people with hypothyroidism may have changes in the small intestine, where bacteria from the colon spread to the small intestine where they usually are not, known as bacterial overgrowth of the small intestine.

In one study, 40 patients had abnormal results on a glucose breath test. After taking the probiotic Bacillus clausii for one month, the test result for 19 participants was typical. Both antibiotics and probiotics have been effective.

In addition, for people with thyroid, autoimmune and inflammatory diseases, supplements such as turmeric and omega-3 fatty acids can help improve inflammation.


There is no way to prevent hypothyroidism, but people who may have an increased risk of having thyroid problems, for example, women during pregnancy, should consult their doctor about the need for more iodine.

Screening is not recommended for those who do not have symptoms unless they have the following risk factors:

  • A history of autoimmune disease.
  • Previous treatment with radiation in the head or neck.
  • Family history of thyroid problems.
  • Use of medications known to affect thyroid function.

These people can undergo tests to detect early signs of the disease. If the tests are positive, they can take steps to prevent the disease from progressing.

There is no evidence that a particular diet can prevent hypothyroidism, and there is no way to prevent hypothyroidism unless you live in a region with low levels of iodine in your diet, for example, in some parts of Southeast Asia and Africa.


A specific diet for hypothyroidism is not recommended, but people should follow a varied and well-balanced diet that is not high in fat or sodium.

In addition, those with primary hypothyroidism may benefit from following a gluten-free diet. The research suggests a link between celiac disease and autoimmune thyroid disease, and both have inflammatory components.

Avoiding gluten can help in non-celestial autoimmune diseases, but it is essential to first talk to a doctor before eliminating gluten foods. Other foods and nutrients can be dangerous, especially if consumed in large quantities.

These include:

  • Soy, since it can affect the absorption of thyroxine.
  • Iodine is found in seaweed and other marine algae and supplements, including some multivitamins.
  • Iron supplements since can affect the absorption of thyroxine.
  • Cruciferous vegetables such as cauliflower, kale, and cabbage may contribute to a goiter, but only in vast quantities.
  • The consumption of additional iodine can interfere with the balance involved in the treatment. If hyperthyroidism develops, iodine can be dangerous. Any change in diet or supplementation should be discussed with a doctor.