Underactive thyroid (hypothyroidism)

In hypothyroidism, the thyroid gland does not produce enough thyroid hormone. These hormones are essential for regulating metabolism, and a deficiency can cause many bodily processes to slow down.

Cause

The most common cause of hypothyroidism is an autoimmune condition such as Hashimoto’s disease, in which the immune system attacks the thyroid gland and reduces hormone production. Other possible causes include treatment for an overactive thyroid (hyperthyroidism), iodine deficiency, or thyroid surgery.

The condition is more common in women than men, and the risk increases with age.

Symptoms

The following symptoms may occur:

  • Fatigue
  • Weight gain without apparent cause
  • Cold intolerance
  • Dry skin and hair
  • Slow heartbeat
  • Swollen face, hands and feet

Diagnosis

Blood tests to measure thyroid hormone levels are essential for making the diagnosis. In some cases, an ultrasound scan of the thyroid gland may also be required.

Treatment

Treatment of hypothyroidism focuses on replacing the missing thyroid hormones and restoring normal metabolic function. This is usually achieved with synthetic thyroid hormone.

Aftercare

If you are being treated for hypothyroidism, it is important to have your hormone levels checked regularly. As hypothyroidism is a chronic condition, lifelong medication is usually required. Maintaining a healthy lifestyle with a balanced diet and regular exercise can help manage symptoms more effectively.