Is Graves' disease (GD) a hypothyroid condition?

Graves' Disease is a Hyperthyroid Condition, Not Hypothyroid

No, Graves' disease is definitively a hyperthyroid condition—it is the most common cause of hyperthyroidism, responsible for 95% of hyperthyroidism cases in pregnancy and characterized by excessive thyroid hormone production. 1

Pathophysiology

Graves' disease is an autoimmune disorder where:

• Autoantibodies bind to and stimulate the thyroid-stimulating hormone receptor (TSHR), acting as agonists that cause excessive thyroid hormone secretion 2, 3
• This releases the thyroid gland from normal pituitary control, resulting in unregulated hormone production 3
• The condition causes thyroid hypertrophy and stimulation of function through anti-TSH-receptor antibodies (TRAb) 2

Diagnostic Features Confirming Hyperthyroidism

Laboratory findings include:

• Elevated free thyroxine (FT4) or free thyroxine index (FTI) 1, 4
• Suppressed TSH levels (typically <0.1 mU/L) 1, 5
• Presence of thyroid-stimulating immunoglobulins and TRAb 2, 6

Clinical manifestations of hyperthyroidism include:

• Tremors, nervousness, insomnia, excessive sweating 1
• Heat intolerance, tachycardia, hypertension 1
• Weight loss, palpitations, anxiety, diarrhea 1
• Goiter (diffuse thyroid enlargement) 1, 5

Distinguishing from Hypothyroidism

Graves' disease presents opposite to hypothyroidism:

• Hypothyroidism shows high TSH with low free T4, along with fatigue, weight gain, cold intolerance, and constipation 1
• Graves' disease shows low/suppressed TSH with high free T4, along with hypermetabolic symptoms 1, 5

Important Caveat

After treatment of Graves' disease, patients may develop hypothyroidism:

• Radioactive iodine therapy causes hypothyroidism in 70-100% of patients at 10 years 5
• Thyroidectomy results in lifelong hypothyroidism requiring hormone replacement 2
• This is a consequence of treatment, not the disease itself 2, 3