hormonal and metabolic disorders
Hyperthyroidism
Diagnosis of Hyperthyroidism
Thyroid function tests Doctors usually suspect hyperthyroidism on the basis of the symptoms and findings on physical examination, including increased heart rate and blood pressure. Thyroid function tests are used to confirm the diagnosis. Often, testing begins with measurement of thyroid-stimulating hormone (TSH). If the thyroid gland is overactive, the level of TSH is low. However, in rare cases in which the pituitary gland is overactive, the level of TSH is normal or high. If the level of TSH in the blood is low, doctors measure the levels of the thyroid hormones in the blood. If there is a question of whether Graves disease is the cause, doctors check a sample of blood for the presence of antibodies that stimulate the thyroid gland (thyroid-stimulating antibodies). If a thyroid nodule is suspected as the cause, a Thyroid ultrasound will show whether the nodule is overactive, that is, whether it is producing excess hormones. Such a scan may also help doctors in their evaluation of Graves disease. In a person with Graves disease, the scan shows the entire gland to be overactive, not just one area. In thyroiditis, the scan shows low activity because of the inflammation. 