Hypothyroidism is a condition where the thyroid gland produces insufficient thyroid hormones, which are critical for regulating metabolism, energy, and body functions. Common symptoms include fatigue, weight gain, dry skin, constipation, cold intolerance, hair thinning, and slowed thinking. It can result from autoimmune disease (Hashimoto’s thyroiditis), nutritional deficiency, certain medications, or thyroid surgery. Left untreated, hypothyroidism can lead to complications such as heart problems, infertility, and myxedema, a rare but life-threatening condition. With proper diagnosis and functional medicine based therapy, most individuals can restore normal function, improve energy, and maintain long-term health.