HYPERTHYROIDISM – INVESTIGATIONS
Laboratory investigations include the following:
I. Thyroid Function test
- Serum TSH level: TSH levels are decreased in hyperthyroidism
- Serum T4 level: Serum T4 is increased
- Serum T3 level: Serum T3 is increased
- Resin T3 uptake test: Resin T3 uptake is increased
- Radioactive iodine uptake test: Radioactive iodine uptake is high in hyperthyroidism
II. TSH receptor antibody (TSH-R Ab): It is high in 80% of cases.
III. Other blood test:
- Increased blood calcium level (hypercalcemia) and alkaline phosphatase
- Increased ESR (Erythrocyte sedimentation rate) in thyroiditis
IV. Electrocardiogram (ECG or EKG) and Echocardiography (ECHO) may be required in case of heart involvement.