Overview#
Hyperthyroidism is a condition in which the thyroid gland produces excessive thyroid hormones (T3 and T4), accelerating the body's metabolism. Graves' disease, an autoimmune disorder, accounts for 60-80 % of cases. The condition is 5-10 times more common in women than men. In India, the prevalence is estimated at 1-2 % of the population, with many cases going unrecognized in the early stages.
Causes & Risk Factors#
- Graves' disease – autoimmune antibodies (TSI) stimulate the thyroid to overproduce hormones.
- Toxic multinodular goitre – autonomous thyroid nodules that produce hormones independently of TSH; common in older Indians.
- Thyroiditis – inflammation (viral or postpartum) causing temporary release of stored hormones.
- Excessive iodine intake – supplements, iodine-rich contrast dyes, or amiodarone.
- Family history of autoimmune thyroid disease increases risk significantly.
Signs & Symptoms#
- Unintentional weight loss despite increased appetite
- Rapid or irregular heartbeat (palpitations), sometimes atrial fibrillation
- Tremor of the hands and fingers
- Heat intolerance and excessive sweating
- Nervousness, anxiety, and irritability
- Frequent loose stools or diarrhea
- Menstrual irregularities (lighter or missed periods)
- Bulging eyes (exophthalmos) – specific to Graves' disease
Diagnosis#
- TSH – suppressed (< 0.1 mIU/L) is the hallmark. Book Thyroid Profile
- Free T3 and Free T4 – elevated; sometimes only T3 is elevated (T3-thyrotoxicosis).
- TSH Receptor Antibodies (TRAb) – positive in Graves' disease.
- Radioactive Iodine Uptake (RAIU) scan – differentiates Graves' from thyroiditis.
- Complete Blood Count – to monitor for agranulocytosis if starting anti-thyroid drugs. Book CBC
Treatment Options#
Anti-thyroid drugs (ATDs): Methimazole (carbimazole in India) is first-line. Propylthiouracil (PTU) is used in the first trimester of pregnancy. Treatment typically lasts 12-18 months. Regular blood tests monitor liver and white blood cell counts.
Radioactive iodine therapy: A single oral dose destroys overactive thyroid tissue. Most patients become hypothyroid afterward and need lifelong levothyroxine.
Surgery (thyroidectomy): Reserved for large goitres, suspected malignancy, or patients who cannot tolerate other treatments.
Supportive care: Beta-blockers (propranolol) provide quick symptom relief for palpitations and tremor while ATDs take effect.
Prevention#
- There is no proven way to prevent autoimmune hyperthyroidism, but early detection limits complications.
- Avoid excessive iodine supplementation unless directed by a doctor.
- If you have a family history of thyroid disease, get annual thyroid function tests.
- Women planning pregnancy should get thyroid screening, as uncontrolled hyperthyroidism raises miscarriage risk.
When to See a Doctor#
See a doctor promptly if you experience unexplained weight loss, persistent palpitations, tremor, or heat intolerance. Seek emergency care for thyroid storm – a life-threatening escalation marked by high fever (> 104 °F), extreme tachycardia, agitation, delirium, and vomiting. This requires immediate hospitalization.