Graves' Disease is the Most Common Cause of Hyperthyroidism
Statement A is correct: Graves' disease is indeed the most common cause of hyperthyroidism. According to authoritative guidelines and recent research, Graves' disease accounts for approximately 70% of hyperthyroidism cases and has a global prevalence of 2% in women and 0.5% in men 1, 2, 3, 4.
Analysis of Each Statement
Statement A: Graves' Disease as Most Common Cause ✓ CORRECT
Multiple high-quality sources confirm this:
- Graves' disease represents 70% of hyperthyroidism cases 4
- Other common causes include toxic nodular goiter (16%), thyroiditis (3%), and drug-induced hyperthyroidism (9%) 1, 2, 4
- The U.S. prevalence of hyperthyroidism is approximately 1.2% (0.5% overt, 0.7% subclinical), with Graves' disease being the predominant etiology 2, 3
Statement B: More Common in Men ✗ INCORRECT
Graves' disease is actually more common in women:
- Female sex is a documented risk factor for hyperthyroidism 1
- Global prevalence: 2% in women versus 0.5% in men 3
- This represents a 4:1 female-to-male ratio
Statement C: Majority After Age 60 ✗ INCORRECT
Hyperthyroidism does not predominantly occur after age 60:
- While advancing age is a risk factor for thyroid dysfunction generally 1, hyperthyroidism affects all age groups
- The prevalence is approximately 1.2% in the general U.S. population 2
- Subclinical hyperthyroidism occurs in about 1% of men and 1.5% of women over age 60 5, but this does not represent the majority of cases
Statement D: Not Accompanied by Autoantibodies ✗ INCORRECT
Autoantibodies are frequently present in hyperthyroidism:
- Graves' disease (the most common cause) is an autoimmune condition characterized by TSH-receptor antibodies 1, 6
- Hashimoto thyroiditis, which can cause hyperthyroidism, involves thyroid peroxidase antibodies 4
- The presence of autoantibodies is actually a key diagnostic feature in many hyperthyroidism cases
Statement E: Nodules Necessary for Diagnosis ✗ INCORRECT
Nodules are not required for hyperthyroidism diagnosis:
- Graves' disease typically presents with a diffusely enlarged thyroid gland without discrete nodules 3
- Diagnosis is based on biochemical tests (low TSH, elevated free T4 and/or T3) 1, 4
- While toxic nodular goiter and toxic adenoma involve nodules, these account for only a minority of cases
- Thyroid ultrasound is not recommended as first-line diagnostic testing 6
Clinical Implications
The correct identification of Graves' disease as the most common cause has important treatment implications. Common causes of hyperthyroidism include Graves' disease, Hashimoto thyroiditis, and functional thyroid nodules, with treatment options including antithyroid medications (such as methimazole), radioactive iodine ablation, and surgery 1. The specific etiology determines the optimal therapeutic approach and prognosis.