Graves' disease
The most common cause of an overactive thyroid. An autoimmune antibody switches the thyroid permanently 'on', flooding the body with thyroid hormone. It is the hyperthyroid mirror-image of Hashimoto's, and can also affect the eyes.
What it is
Graves' disease is an autoimmune disorder in which the immune system makes an antibody (TSH-receptor antibody, TRAb) that mimics TSH and continuously stimulates the thyroid to overproduce hormone. The result is thyrotoxicosis — a body running too fast. It is the commonest cause of hyperthyroidism, affects women far more than men, and often appears between 20 and 50. Uniquely, the same antibody can inflame the tissues behind the eyes (Graves' orbitopathy), causing bulging, gritty or double vision, and can rarely affect the skin over the shins. Blood tests show a suppressed TSH with high free T4 and/or free T3; a positive TRAb (or TPO antibody) confirms the autoimmune cause and separates it from other forms of hyperthyroidism.
Key lab markers
- TSH — suppressed (low/undetectable); the most sensitive screen for hyperthyroidism.
- Free T4 and Free T3 — elevated; T3 often disproportionately high in Graves'.
- TSH-receptor antibody (TRAb) — the specific confirmatory test for Graves'.
- Anti-TPO antibody — often positive, supports autoimmune thyroid disease.
- Thyroid uptake scan — diffuse increased uptake if the diagnosis is unclear.
- Full blood count, LFTs — baseline before antithyroid drug treatment (rare marrow and liver effects).
Symptoms
- Weight loss despite a normal or increased appetite
- Rapid or irregular heartbeat, palpitations
- Heat intolerance, excessive sweating
- Tremor of the hands, anxiety, restlessness, irritability
- Frequent bowel movements
- Insomnia, muscle weakness
- Neck swelling (goitre)
- Eye changes — bulging, gritty, watery or double vision (Graves' orbitopathy)
- Lighter or absent periods
Related lab panels
When to discuss with a doctor
A suppressed TSH with a high free T4/T3 needs prompt medical review — untreated thyrotoxicosis strains the heart and bone. Palpitations with an irregular pulse (atrial fibrillation), fever with confusion, or severe agitation are urgent, as is any new or worsening eye involvement. Treatment options — antithyroid drugs (carbimazole/methimazole), radioactive iodine, or surgery — are chosen with an endocrinologist and often bring the thyroid back to normal or under-active (then replaced). Beta-blockers ease symptoms while definitive treatment takes effect. Mediora.AI flags the suppressed-TSH / high-T4 pattern and antibody status; the diagnosis and treatment choice belong with endocrinology.