Hypothyroidism, also known as underactive thyroid, is a condition in which the thyroid gland doesn't produce enough thyroid hormones. The thyroid is a small, butterfly-shaped gland located at the base of your neck, and it plays a crucial role in regulating your metabolism.

What Does the Thyroid Do?

The thyroid gland produces two main hormones: thyroxine (T4) and triiodothyronine (T3). These hormones affect nearly every cell in your body and help control:

  • Metabolism and energy production
  • Heart rate and body temperature
  • Brain development and function
  • Muscle strength
  • Skin health
  • Menstrual cycles
  • Weight management

Common Causes of Hypothyroidism

Several factors can lead to an underactive thyroid:

  • Hashimoto's thyroiditis: The most common cause, an autoimmune condition where the immune system attacks the thyroid
  • Thyroid surgery: Removal of all or part of the thyroid
  • Radiation therapy: Treatment for head and neck cancers
  • Certain medications: Lithium, amiodarone, and others
  • Iodine deficiency: Less common in developed countries with iodized salt
  • Congenital hypothyroidism: Being born without a functioning thyroid

How Is It Diagnosed?

Hypothyroidism is diagnosed through blood tests that measure:

  • TSH (Thyroid Stimulating Hormone): Elevated TSH often indicates hypothyroidism
  • Free T4: Low levels confirm the diagnosis
  • Thyroid antibodies: To check for Hashimoto's thyroiditis

If you suspect you have hypothyroidism, consult with your healthcare provider for proper testing and diagnosis.