The thyroid gland, a small gland located at the base of your throat, produces thyroid hormones which control metabolism. When insufficient thyroid hormone is produced, it creates a condition known as hypothyroidism. On the other hand, the excess production of thyroid hormone results is hyperthyroidism.

When thyroid hormone levels are low, the brain sends a chemical signal to the pituitary gland to produce more hormones to stimulate the thyroid. This causes the thyroid gland to produce more thyroxine. Thyroid diseases range from common and relatively harmless goiter to life-threatening cancer. Hence, it is important to be aware of thyroid disease and its causes, symptoms, and types.

Causes
There are different types of thyroid diseases and their causes need to be looked at carefully to form an objective assessment. Some of the causes of thyroid disorders are:

• Hyperthyroidism
  Hyperthyroidism can be caused by several factors. One of these is the inflammation of the thyroid gland. This causes the gland to produce excess hormones. It could also be caused by a cancerous tumor in the thyroid gland, or the pituitary gland could be producing excess thyroid-stimulating hormones. Sometimes, a goiter may develop in the thyroid gland and give rise to nodules that secrete thyroxin. As a result, the body might become chemically imbalanced.
• Hypothyroidism
  The scarcity of thyroid hormones leads to hypothyroidism, which may be caused by an immune system disorder. In this, the thyroid tissue is damaged due to an attack on the immune system. Surgical removal of the thyroid gland, due to the disease, may also cause hypothyroidism. Taking lithium and being exposed to too much iodine may also lead to this condition.
• Thyroid Cancer
  While the exact causes of thyroid cancer are not known, being exposed to radiation and suffering from an iodine deficiency are some of the known risk factors. If any of your blood relatives have been diagnosed by cancer, it increases the chances of you having it as well.

Symptoms
Thyroid disease symptoms are caused by an imbalance in the levels of thyroid hormones or due to cancerous growth in the gland. The symptoms depend on what kind of thyroid disorder the patient is suffering from. They need to be categorized to fully understand thyroid disease and its causes, symptoms, and types. Some of the common symptoms include:

• Hypothyroidism
  The symptoms of hypothyroidism include loss in appetite, feeling cold and tired, gaining excess weight, depression, mental activity slowing down, coarse skin and hair, joint pain, elevated cholesterol levels, memory loss, goiter, constipation, and muscle pain.
• Hyperthyroidism
  Hyperthyroidism may cause sweating, fragile hair, increased appetite, intolerance to heat, getting irritated or agitated easily, and increased heart rate.

• Thyroid cancer
  The symptoms of thyroid cancer include incessant coughing, a rapidly growing lump in the neck region, breathing problems, and difficulty swallowing food. Sometimes, there could be pain in the throat, which moves up to the ears, turning your voice hoarse. Thyroid diseases can cause a lot of discomfort and pain and a decrease in the overall quality of life. But, with proper treatment and a few lifestyle adjustments, the symptoms can be managed effectively.