Thyroid
The thyroid gland, located in the front of the neck just below the Adam’s apple, takes iodine from the diet and makes thyroid hormone. Thyroid hormone affects a person’s physical energy, temperature, weight and mood.
Thyroid diseases generally fall into two broad groups of disorders: abnormal function and abnormal growth (nodules) in the gland. These problems are common in the general population, especially among older people and women. Most thyroid problems can be detected and treated.
Functional disorders are usually related to the gland producing too little thyroid hormone (hypothyroidism) or too much thyroid hormone (hyperthyroidism).
Benign nodules in the thyroid gland are common and do not usually cause serious health problems. These nodules occur when the cell growth within the nodule is abnormal. Nodules can occasionally put pressure on the neck and cause trouble with swallowing, breathing or speaking if they are too large. The thyroid usually functions normally even when nodules are present.
Thyroid cancers are much less common than benign nodules. With treatment, the cure rate for thyroid cancer is more than 90 percent.
Checking for Thyroid Disease
Checking for thyroid disease is similar to other kinds of medical evaluations. The doctor considers the patient’s medical history, examines the thyroid and may order a blood test or other diagnostic tests.
A standard physical examination of the thyroid gland is done by palpation – that is, feeling the thyroid gland. The doctor feels for the size and texture of the gland, and whether any masses or nodules are present.
Testing for Thyroid Function
There are two standard blood tests of thyroid function: the measurement of thyroid hormone, usually T4, and the measurement of thyrotropin (TSH). TSH is a hormone secreted from the pituitary gland that controls how much thyroid hormone the thyroid makes.
Abnormal blood tests usually reveal thyroid function problems and not the presence of thyroid nodules or cancer.
Testing for Nodules
If a nodule is found during the physical examination, a test called fine needle aspiration (FNA) biopsy may be done to help find out whether the nodule is cancerous or benign. In addition, a thyroid nuclear scan may help the doctor evaluate thyroid function or nodules. The scan is performed by giving the patient a radioisotope and taking a special picture to see how much of the radioisotope is taken up by the thyroid gland.
A thyroid ultrasound scan is a diagnostic test that shows a picture of the anatomy, or structure, of the thyroid gland. Ultrasound is most often used to determine if a nodule is solid or cystic. Cystic nodules, containing only fluid, are usually benign.
Ultrasound is not usually performed as a routine screening test for thyroid nodules in the general population. The reason is that small, nonpalpable ultrasound abnormalities are very common in people without evidence of thyroid disease.
Symptoms of Abnormal Thyroid Function
Too Little Thyroid Hormone Hypothyroidismr | Too Much Thyroid Hormone Hyperthyroidism |
|---|---|
|
|
|
|
|
|
|
|
|
|
|
|