Hyperthyroidism: Hyperthyroidism is a condition characterized by the overproduction of thyroid hormones by the thyroid gland. Common causes include Graves' disease, multinodular goiter, and toxic adenoma. Symptoms can vary widely among individuals and may include irritability, muscle weakness, sleeping difficulties, rapid heartbeat, heat intolerance, diarrhea, thyroid enlargement, hand tremors, and weight loss. While symptoms are often less severe in the elderly and during pregnancy, a rare but life-threatening complication known as thyroid storm can occur, leading to confusion and high fever, sometimes resulting in death. Treatment options depend on the underlying cause and severity of the condition and may include radioiodine therapy, medications, or thyroid surgery.

Hypothyroidism: Hypothyroidism is a disorder of the endocrine system characterized by insufficient production of thyroid hormones by the thyroid gland. Symptoms may include intolerance to cold, fatigue, constipation, slow heart rate, depression, weight gain, and occasionally, swelling of the neck due to goiter. Untreated hypothyroidism during pregnancy can lead to developmental delays and congenital iodine deficiency syndrome in the baby. Diagnosis of hypothyroidism involves blood tests to measure thyroid-stimulating hormone (TSH) and thyroxine levels. Treatment typically involves supplementation with levothyroxine, though newer modalities like liothyroxine may be beneficial for patients with persistent symptoms despite treatment with levothyroxine.