Does a thyroid ultrasound test for hypo and hyperthyroidism?

Not reliable: It can give you some clues about hypo or hyper but it cannot tell you for sure about thyroid function. The only test to do that is the blood test.

No: The thyroid ultrasound is not a good test to look for hypo or hyperthyroidism, but it can give information about why a person is hypothyroid or hyperthyroid. Hyperthyroidism can be due to 1) graves' disease, which often has an enlarged thyroid with increased blood flow, or a 'toxic' nodule. Hypothyroidism is often due to hashimoto's thyroiditis, with a mottled, or 'heterogenous' appearance.

Thyroid ultrasound: Thyroid ultrasound is done when there is enlargement of thyroid gland, or goiter.Goiter may be accompanied with hypothyroid or hyperthyroid condition and thyroid adenoma or nodule.