Hypothyroidism - Symptoms, Risk factors and Treatment

The thyroid gland is a butterfly-shaped organ located in front of the neck, wrapped around the windpipe. It is responsible for producing thyroid hormones, which play an important role in the body’s metabolism.

In hypothyroidism, the thyroid gland becomes underactive and produces little amounts of thyroid hormone than the amount the body requires.

What hormones does the thyroid gland produce?

The thyroid gland produces two hormones, commonly known as T3 and T4. T3 and T4 are also known as triiodothyronine and thyroxine, respectively. The thyroid hormones utilize iodine. The T3 hormone contains three iodine atoms, and the T4 hormone contains four iodine atoms. Most of the T4 is converted to T3, which is the active form. 

The thyroid gland itself is under control of a hormone called TSH ( thyroid-stimulating hormone ), produced by the pituitary gland located in the skull.

The thyroid hormones have their effect on almost every organ and cell of the body. Their primary function is to increase metabolism and energy consumption. Metabolism is when your body uses energy molecules such as carbohydrates, proteins, and fats along with oxygen to make ATP, a molecule by which our cells use energy.

What causes hypothyroidism?

Hypothyroidism can be caused by different conditions such as:

Thyroiditis: 

Thyroiditis means inflammation of the thyroid gland. 

There are different types of thyroiditis such as Hashimoto thyroiditis, subacute granulomatous thyroiditis, and silent lymphocytic thyroiditis. In thyroiditis, the body’s immune system attacks the thyroid gland. It is the most common cause of primary hypothyroidism. The thyroid gland contains thyroid hormone in stored form (thyroid follicles). 

When the immune system attacks the thyroid gland, the follicles get damaged resulting in an increased release of pre-stored thyroid hormone, causing transient hyperthyroidism, followed by hypothyroidism. 

Post-therapeutic hypothyroidism:

It is the second most common cause of primary hypothyroidism. In this condition, hypothyroidism results after a medical or surgical treatment such as radiation therapy for cancer, thyroid surgery for cancer, hyperthyroidism or goiter, and medications such as propylthiouracil, etc.

Thyroid nodules:

Thyroid nodules are growths in the thyroid gland which may be solid or filled with fluid. They can be associated with hypothyroidism (as in associated with Hashimoto's thyroiditis) or hyperthyroidism (if the nodules produce thyroid hormone) and can show different symptoms, respectively. If the nodules enlarge in size, the size of the thyroid gland may enlarge, causing additional symptoms like hoarseness of voice, pain, trouble in swallowing or breathing.

Iodine deficiency:

Severe iodine deficiency can cause hypothyroidism, which may result in infertility, increased risk of stillbirth, and abortions in adults. If a pregnant woman has a severe iodine deficiency, it can cause mental retardation in the baby.

Symptoms of hypothyroidism:

The symptoms of hypothyroidism include:

• Tiredness and fatigue
• Dry skin
• Sensitivity to cold weather
• Constipation
• Depression
• Lethargy
• Memory problems
• Confusion
• Weight gain
• Slow heart rate
• Puffy face
• Menstrual irregularities

Complications of hypothyroidism:

Myxedema coma: It is a complication of chronic hypothyroidism in which coma (loss of consciousness) occurs along with low body temperature and respiratory problems. If not treated on time, it can result in death.

Diagnosis of hypothyroidism:

Hypothyroidism is primarily diagnosed by checking the levels of thyroid hormones that involve:

• T3
• T4
• TSH

Other than that, your doctor may suggest other tests such as a Radioiodine scan, MRI, CT scan, PET scan, or a thyroid biopsy to make a definite diagnosis.

Treatment of hypothyroidism:

The treatment of hypothyroidism is mainly based upon hormonal replacement therapy, in which a synthetic thyroid hormone drug called levothyroxine is given which works like the body's thyroid hormone.

Conclusion:

The thyroid gland plays a vital role in the body's normal functioning. Many diseases can affect the thyroid gland, and early detection and treatment of the disorder are of paramount importance. If you experience any symptoms of hypothyroidism, it is highly recommended to see your healthcare provider.