The term hypothyroidism refers to an underactive thyroid gland. The thyroid gland is located in the neck and is an important endocrine organ that produces the thyroid hormones, important hormones responsible for the regulation of metabolism.
Some of the common signs and symptoms of hypothyroidism include weight gain, fatigue, depression, sensitivity to the cold, dry skin and hair, muscle ache, constipation, and loss of libido. In women, the condition can also cause irregular or heavy periods.
If hypothyroidism is left untreated, the thyroid gland may swell and give rise to a goitre or lump in the throat. Other complications that may eventually occur include heart disease, pregnancy problems and even a life-threatening condition called myxoedema, where extremely low thyroid hormone levels cause hypothermia, confusion and drowsiness. In children, hypothyroidism can delay growth and impair intellectual ability, symptoms that are referred to as cretinism in severe cases.
Diagnosis of this condition is based on symptoms and blood tests to assess the thyroid-stimulating hormone (TSH) and thyroxine level. Hypothyroidism is managed with hormone replacement therapy to help raise the thyroxine level. Patients normally require life-long treatment, but are usually able to lead a healthy and active lifestyle.
The most common cause of hypothyroidism is an autoimmune condition called Hashimoto’s thyroiditis. Here, various immune cells and antibodies present in the body attack the thyroid gland. Hypothyroidism is more common among women than men, affecting 15 in every 1000 women compared with 1 in every 1000 men.
Reviewed by Sally Robertson, BSc