HYPOTHYROIDISM – INVESTIGATIONS
Detailed medical history: This includes the description of symptoms by the patient. The doctor also checks for characteristic signs of hypothyroidism in skin, hair, heart, and abdomen.
Physical examination: It is done with particular attention to the thyroid gland which is sometimes (not always) enlarged.
I. Thyroid Function test
- Serum TSH level: TSH levels are increased in hypothyroidism but it may be normal or low in some cases (secondary hypothyroidism)
- Serum T4 level: Serum T4 is decreased.
- Serum T3 level: Serum T3 is decreased.
- Resin T3 uptake test: Resin T3 uptake is decreased.
- Free Thyroxine index: It is decreased in cases of hypothyroidism.
- Radioactive iodine uptake test: Radioactive iodine uptake is also decreased.
II. Antibodies against thyroperoxidase and thyroglobulin: The antibody level is high in patients with Hashimoto’s thyroiditis.
III. Other blood tests: Serum cholesterol, liver enzymes, and creatinine kinase are increased in hypothyroidism.
IV. Electrocardiogram (ECG or EKG) and Echocardiography (ECHO) may be required to see involvement of heart.
V. X-ray chest may be needed to detect lung involvement.