The thyroid gland is essentially a small gland located in the lower part of the neck which is in the shape of a butterfly. The function of this gland is to secrete hormones and regulate the metabolic processes in the body. The two main hormones produced by the thyroid gland are triiodothyronine (T3) and thyroxine (T4). If the gland malfunctions, it can lead to conditions such as hypothyroidism, hyperthyroidism, and goiter, among others.

Hypothyroidism — Causes, symptoms, and Types
Low levels of hormone secretion in the thyroid gland results in hypothyroidism. This signifies that the thyroid gland is underactive, resulting in slow metabolism. Women are more prone to hypothyroidism as compared to men.

• Causes: Hashimoto’s disease, surgical removal of the thyroid gland and excessive iodine levels.
• Symptoms: Cold intolerance, tiredness, depression, and excessive bleeding during menstruation.
• Types: There are three types of hypothyroid disorders. In the case of type 1 hypothyroidism, there is insufficient hormone production, whereas type 2 hypothyroidism is caused due to the body’s inability to use the hormones produced by the thyroid gland. In the case of type 3 hypothyroidism, the body’s immune system attacks the thyroid gland, causing low levels of hormone secretion.

Hyperthyroidism — Causes, Symptoms, and Types
Excessive production of T3 and T4 hormones in the thyroid gland leads to hyperthyroidism.

• Causes: Liver dysfunction, thyroiditis, and Grave’s disease.
• Symptoms: Loss of weight, anxiety, hyperactivity, insomnia, and shortness of breath.
• Types: Hyperthyroidism can be classified into two types; Grave’s disease which is caused due to the body’s autoimmune system and Postpartum thyroiditis, which usually affects women after childbirth.

Goiter
Deficiency of iodine salt causes enlargement of the thyroid gland and this condition is known as goiter. The causes of goiter include Hashimoto’s disease, Grave’s disease, and low intake of iodine. Difficulty in breathing and swallowing are some symptoms of the disease.

Thyroid nodules
Lumps formed inside the thyroid gland are called thyroid nodules. These lumps are either solid or filled with fluid and most of them are non-cancerous. The causes of thyroid nodules are not known and in most cases, they do not show any symptoms.

Thyroiditis
Inflammation caused in the thyroid gland, due to an attack by the immune system, results in thyroiditis. Common symptoms of thyroiditis include lethargy, swelling around the eyes, fever, painful and enlarged thyroid gland. The condition can be classified into five types:

• Hashimoto’s disease
• Postpartum thyroiditis
• Drug-induced thyroiditis
• Subacute granulomatous thyroiditis
• Subacute lymphocytic thyroiditis

Thyroid cancer
A rare form of cancer caused due to abnormal growth of cancer cells in the thyroid gland or in the lining of the thyroid gland is called thyroid cancer. Some causes of this condition are genetic mutation, iodine deficiency, and exposure to high energy rays or radioactive elements. Painful and swollen glands, hoarseness in voice, difficulty in breathing are some symptoms of thyroid cancer. It can be further subdivided into four types:

• Papillary thyroid cancer
• Follicular thyroid cancer
• Medullary thyroid cancer
• Anaplastic thyroid cancer

Although no complete cure is available for thyroid diseases, regular screening, proper medications, diet and lifestyle changes can help in improving the symptoms of the conditions.