Thyroid disorders affect the thyroid gland, a butterfly-shaped gland in your neck that produces hormones essential for regulating your metabolism. Here's a summary of common thyroid disorders: Key Thyroid Disorders:Hypothyroidism (Underactive Thyroid):The thyroid doesn't produce enough thyroid hormones.Symptoms: Fatigue, weight gain, constipation, dry skin, feeling cold, depression. Common cause: Hashimoto's thyroiditis (an autoimmune disease). Hyperthyroidism (Overactive Thyroid):The thyroid produces too much thyroid hormone. Symptoms: Weight loss, rapid heartbeat, anxiety, irritability, tremors, sweating, difficulty sleeping. Common cause: Graves' disease (an autoimmune disease). Thyroid Nodules:Lumps that develop within the thyroid gland. Most are benign, but some can be cancerous. Goiter:Enlargement of the thyroid gland. Can be caused by various factors, including iodine deficiency or thyroid disorders. Thyroid Cancer:Cancer that develops in the thyroid gland. Diagnosis:Blood tests (to measure thyroid hormone levels) Physical examinationUltrasound Thyroid scan Biopsy (for nodules)