In simple words, hypothyroidism is under-active thyroid gland. In such condition, thyroid gland cannot produce enough thyroid hormone to keep the body functioning properly. Thyroid gland is a butterfly shaped endocrine gland, which is located in the lower front of the neck. This thyroid gland produces thyroid hormones that are secreted into the bloodstream and then carried to all the tissues in the body. Individuals with hypothyroidism have low levels of thyroid hormones circulating in the blood.
Surgical Removal of Partial or Entire Thyroid Gland: Individuals with certain clinical disorders such as thyroid cancer, Grave’s diseases or presence of thyroid nodules may need to undergo a partial or complete removal of thyroid gland. If the entire thyroid gland is surgically removed, there will be no production of thyroid hormones, which will definitely lead to hypothyroidism. If the gland is partially removed, it may be able to produce thyroid hormones and maintain normal levels.
Autoimmune Disease: Autoimmune diseases are those in which the immune cells attack body’s own healthy tissues. The production of thyroid hormone (Thyroxine) decreases when immune system attacks the thyroid gland. Such damage leads to underactive thyroid. The most common types of autoimmune reactions are Hashimoto’s Thyroiditis and atrophic Thyroiditis. In addition to this, these disorders are more common in women as compared to men.
Radiation Treatment: Individuals with certain clinical conditions such as thyroid cancer, nodular goitre and Grave’s disease are treated with radioactive iodine. This is done to destroy their thyroid gland and to prevent further damage. Other patients with Hodgkin’s disease and head and neck cancers are also treated with radiation. Such a treatment may kill some healthy thyroid cells along with cancerous cells. Damage caused to thyroid cells may reduce the production of thyroid hormones and lead to an underactive thyroid.
Medications: Certain medications prevent the thyroid gland from producing hormones thus, leading to an underactive thyroid or hypothyroidism. Such medications include –
- Interleukin-2 – used in the treatment of cancer
- Lithium – Used in the treatment of depression, hyperactivity, rushed speech and aggression- manic depressive illness
- Interferon alpha – Used in the treatment of lymphoma, hepatitis B and C
- Amiodarone – Used in the treatment of ventricular fibrillation or tachycardia (irregular or rapid heartbeat)
Congenital Hypothyroidism: Congenital hypothyroidism is a condition in which a baby is born with hypothyroidism. In such cases, few babies are born with partially formed thyroid gland or a complete absence of thyroid gland. In some cases, the thyroid cells or enzymes do not function properly.
Iodine Amount: The thyroid gland requires iodine for the production of thyroid hormones. The food you eat brings iodine into the body, which then travels, through the blood to the thyroid gland. In simple words, right amount of iodine is required for the thyroid gland to function properly. Consuming very little iodine can affect the thyroid gland as well as the production of hormones and may further lead to hypothyroidism.
Thyroiditis: Inflammation of the thyroid gland is called Thyroiditis. This inflammation usually occurs due to a viral infection or an autoimmune attack. Such inflammation may cause the thyroid gland to release all the thyroid hormones into the blood at once, thus causing hyperthyroidism. After this brief period of hyperthyroidism, the thyroid becomes underactive.
Damage Caused to Pituitary Gland: Pituitary gland is the main gland that instructs the thyroid gland how much thyroid hormones to produce. Any damage caused to the main pituitary gland may impair the ability of thyroid to function. Thus, the thyroid gland may not be able to produce sufficient thyroid hormones.
- Easily tired
- Dry and scaly skin
- Constipation and irregular bowel movements
- Slow heart rate
- Dry hair
- Hair loss (brittle hair)
- Hoarse voice
- Muscle weakness
- Muscle cramps
- Weight gain
- Irregular menstrual cycle
- Loss of libido
- Sensitive to cold
Goitre: Goitre is an abnormal swelling of thyroid gland. Iodine is required for the production of thyroid hormones. A deficiency of iodine will lead to under-production of thyroid hormones and this may further lead to hypothyroidism. This decreased production of thyroid hormones will be sensed by the pituitary gland in the brain that will start sending signals to the thyroid gland. This signal is known as ‘thyroid stimulating hormone’ (TSH). This hormone stimulates the thyroid gland to produce more hormones and as a result, thyroid grows in size. This abnormal growth is called ‘goitre’. The most common cause of goitre is Hashimotos Thyroiditis.
Risk of Heart Problems: An individual with hypothyroidism is at increased risk of cardiovascular diseases. It brings changes in the cardiac output, contractility of heart, oxygen consumed by heart, altered heart rate and blood pressure. It also increases the levels of LDL (bad) cholesterol as well as total cholesterol. Such an increase in the blood lipid levels may further lead to deposition of fat in the arteries, thus obstructing the flow of blood. Such a condition may further lead to atherosclerosis. An individual with hypothyroidism must immediately seek medical advice if symptom of cardiovascular diseases such as chest pain appears.
Mental Disorders: Hypothyroidism is always accompanied by psychiatric disorders. Hypothyroidism may lead to intellectual deterioration, poor memory, slowing of mental processes, loss of interest. If hypothyroidism is not checked and treated properly on time, it may further lead to dementia and such individuals can also have permanent brain defects.
Neuromuscular Complaints: Approximately 40% individuals with hypothyroidism have neuromuscular complaints. These neuromuscular complaints mainly include muscle weakness, muscle cramps, muscle pain, muscle stiffness and easily fatigued. Such signs and symptoms may appear after one year of hypothyroidism.
Infertility: Individuals with hypothyroidism may have some fertility problems. However, these fertility problems can be quickly solved if hypothyroidism is treated properly and thyroid function is back to normal. Decreased sexual desire is another common problem in both males and females with hypothyroidism.
Myxedema: It is a condition in which thickening, oedematous, non-pitting changes occurs in the soft tissues of individuals with hypothyroidism. Individuals who have hypothyroidism from a long period and which are not treated properly are often at an increased risk of Myxedema coma. Myxedema coma is a life-threatening condition, which is typically seen in elderly women. Large doses of thyroid hormone are required for the treatment of Myxedema coma.
Tests & Diagnosis
People check their thyroid levels when symptoms appear, especially irregular menses and sudden weight gain. Thyroid function test is a blood test that measures levels of thyroid hormones such as:
- Triiodothyronine (T3)
- Thyroxine (T4)
- Thyroid Stimulating Hormone (TSH)
A high level of thyroid stimulating hormone and a low level of Thyroxine indicate that the person has an underactive thyroid. An individual is at risk of developing hypothyroidism if the blood test reveals a high level of thyroid stimulating hormone and normal levels of Thyroxine.
Hypothyroidism Diet & Food
Include Foods Rich in Zinc
Zinc is a trace mineral, which is required for the synthesis of thyroid hormones. Zinc deficiency may reduce the production of thyroid hormones. Therefore, zinc deficiency can be the cause for sub-clinical hypothyroidism. A research showed that including zinc rich foods in the daily diet or taking zinc supplements improved thyroid function. Foods rich in zinc include:
- Lentils and beans
- Pumpkin seeds
- Sesame seeds
Calcium & Vitamin D
To some extent, hypothyroidism is associated with decreased bone mineral density. Thus, individuals with hypothyroidism are at increased risk of bone fractures.
In addition to this, hypothyroidism is also known as the secondary cause for osteoporosis. Therefore, along with thyroid treatment individuals should include some rich food sources of calcium and vitamin D to improve their bone mineral density. However, too much calcium is said to be goitrogen. Therefore, one should be careful about their calcium intake. Rich sources of calcium include:
- Sesame seeds
- Poppy seeds.
- Bok choy.
- Nuts and oilseeds
- Dark green leafy vegetables
- Foods fortified with calcium
Foods rich in vitamin D include:
- Shiitake mushrooms
Hypothyroidism is an autoimmune disorder. Free radicals and oxygen species play an important role in the development of such autoimmune disorders. Therefore, it is necessary to consume a diet rich in antioxidants as these antioxidants scavenge the free radicals and keep oxidative stress at bay. Therefore, one should eat more of whole grains, fruits and vegetables. Food products made out of refined wheat flour and processed foods do not contain any antioxidants. In fact, they are unhealthy and increase the load of free radicals. Therefore, such foods should be strictly restricted.
Increase Intake of Vitamin B12
Research has shown that individuals with hypothyroidism are at increased risk of developing vitamin B12 deficiency. Some symptoms of vitamin B12 deficiency include impaired memory, depression, weakness and numbness. Furthermore, studies have showed that including rich sources of vitamin B12 in daily diet or taking B12 supplements improved the symptoms.
Iodine is extremely important, as it is required for the synthesis of thyroid hormones. Gradually increasing the iodine intake improves the synthesis of thyroid hormones. Large doses of iodine may in turn have a negative effect on thyroid function. Rich sources of iodine include:
- Iodized salt.
- Sea vegetables.
Things to Avoid
Agents that interfere with thyroid function and pose a danger of thyroid disease are known as goitrogens. These goitrogens act directly or indirectly on thyroid gland and alter the metabolism and excretion of thyroid hormones. Such anti-thyroid compounds can enter air, water and food exposure pathways thus becoming an important environmental goitrogenic factor. Dietary Goitrogens include:
- Soy and soy products such as soy flour, soy milk and tofu
- Chinese cabbage
- Brussels sprouts
- Collard greens
Anti-Thyroid Drugs Include
- Anti-tuberculosis drug (ethionamide)
- Anti-fungal agent (ketoconozole)
- Chemotherapeutic agents
- Anticonvulsive (amphenone)
- Hypoglycemic agents (sulfonylureas)