Hypothyroidism is a condition in which the body has insufficient levels of thyroid hormones. As a result, metabolic processes slow down, and the functions of various organs and body systems may be affected.

Possible symptoms include fatigue, drowsiness, sensitivity to cold, dry skin, constipation, and weight gain. One of the most common causes is autoimmune thyroiditis, also known as Hashimoto’s disease. Diagnosis primarily involves measuring thyroid-stimulating hormone (TSH) and free T4 levels in the blood.