Hypothyroidism is a condition in which an individual’s thyroid gland is underactive and does not produce a sufficient amount of hormones. It causes an imbalance of chemical reaction in the body, and leads to symptoms such as obesity, joint pain, heart disease and infertility. Common causes of hypothyroidism include autoimmune disease, radiation treatment and surgical removal of the thyroid. Females, especially 60 years old and above, are more likely to have hypothyroidism. Synthetic thyroid hormones are usually prescribed to treat hypothyroidism.