Diagnostic Tests for Thyroid Disease Problems with energy, mental capacity, and weight may be due to thyroid disease.

The thyroid is a small, yet powerful gland in the neck that releases hormones that help regulate many of the body's functions. One of those hormones is thyroxine, which is necessary for the heart, brain, and other organ systems to function properly.

While thyroid disease can lead to a variety of potentially serious symptoms, including fatigue, anxiety, palpitations, forgetfulness, high blood pressure, and fluctuations in weight, it’s fairly simple to diagnose.

There are many different causes of thyroid disease, but they all lead to one of two issues regarding thyroid function. The thyroid either produces too much hormone (hyperthyroidism), or too little (hypothyroidism). Under normal circumstances, the pituitary gland in the brain tells the thyroid how much hormone it should release. But sometimes infections, medications, and even the body's own immune system can interrupt communication between the pituitary and the thyroid. When this happens, thyroid function becomes altered.

A simple blood test can provide important information about several hormones related to thyroid function, including: TSH. Thyroid-stimulating hormone (TSH) T4 (thyroxine). T3 (triiodothyronine) Thyroid antibody.

Thyroid-stimulating hormone (TSH) is what the pituitary gland releases to tell the thyroid when to produce thyroid hormones. A low level of TSH in the blood usually means that thyroid function is excessive (hyperthyroidism), while a high level of TSH generally indicates that too little thyroid hormone is being produced (hypothyroidism).

T4 (thyroxine). An excess of T4 in the blood is indicative of an overactive thyroid, whereas low levels of T4 indicate underactive thyroid function. Testing T4 blood levels also helps doctors pinpoint whether or not thyroid disease is due to a problem in the pituitary gland or the thyroid gland itself.

T3 (triiodothyronine). T3 is another important thyroid hormone T3 (triiodothyronine). T3 is another important thyroid hormone. T3 levels can fluctuate quite a bit, but high levels of T3 are typically due to hyperthyroidism, while low levels are caused by hypothyroidism.

Thyroid antibody. Autoimmune thyroid diseases (like Hashimoto's thyroiditis or Graves' disease) cause the immune system to release proteins called antibodies that attack the thyroid as if it were foreign tissue. Blood tests can reveal the presence of thyroid antibodies and allow doctors to diagnose such an autoimmune disease.

If your blood tests indicate that you have a thyroid problem, but don't provide enough information for a clear diagnosis, you may need additional thyroid tests. Thyroid Disease: Other Tests Radioactive iodine uptake (RAIU) Thyroid scan. Ultrasound.

Other tests that can help diagnose thyroid disease include: Radioactive iodine uptake (RAIU). The thyroid gland uses iodine in the blood to make thyroid hormones. Swallowing a small, radioactive iodine pill helps doctors measure how much iodine your thyroid gland uses. If the thyroid gland draws upon a lot of the iodine released by the pill (leading to a high RAIU reading), hyperthyroidism is probably the cause. A low RAIU usually reflects an under active thyroid.

Thyroid scan. Often used along with RAIU, a thyroid scan can reveal specific regions in the thyroid that are using either too much or too little radioactive iodine. This scan can help doctors decide whether a thyroid biopsy is necessary to confirm the diagnosis.

Ultrasound. Ultrasound images of the thyroid can show underlying structural causes of thyroid disease such as a tumor or cyst.

Diagnosing thyroid disease, determining the cause, and starting treatment can help prevent serious health complications like heart disease and mental health problems. Thyroid tests are easily done and relatively painless, usually only requiring a blood sample or imaging test. Once properly diagnosed, thyroid disease symptoms can generally be managed effectively.

Under normal circumstances, the immune system, releases proteins called antibodies that help the body fight off viruses and bacteria. Sometimes though, an autoimmune disease can develop, causing the immune system to go haywire and create antibodies that attack the body's own organs. Hashimoto's disease, or Hashimoto's thyroiditis, occurs when the immune system attacks the thyroid gland, causing damage that prevents the thyroid from producing enough thyroid hormone. This condition, called hypothyroidism, results in a number of symptoms ranging from loss of energy to weight gain, thinning hair, constipation, and depressed mood.

Symptoms of Hashimoto’s Thyroiditis Hashimoto's thyroiditis can cause a variety of symptoms, including: Unexplained weight gain Unusual weakness and fatigue Lack of energy Depression Inability to tolerate coldness Pain in the joints and muscles Hair loss Weakened fingernails Thickened skin Swelling of the feet, hands, and face A hoarse voice, problems swallowing, or a tight feeling in the throat Constipation Irregular periods Goiter (swelling of the thyroid gland that causes a lump in the neck)

Complications and Health Risks If left untreated, Hashimoto's thyroiditis can lead to serious complications and long-term health problems. Pregnant women need close monitoring and careful treatment of Hashimoto's disease to prevent birth defects, including mental retardation and other health problems. Untreated Hashimoto's thyroiditis can cause: An enlarged heart Heart failure Myxedema coma, a loss of consciousness caused by profoundly low thyroid hormone levels Mental confusion Infertility or miscarriage

After you're diagnosed, the disease can be easily managed with a daily hormone pill to help keep you symptom-free.

Sometimes, the body's defense system, the immune system, can mistakenly attack its own organs and tissues as a result of an autoimmune disorder. Graves' disease is a form of hyperthyroidism, or overactive thyroid. An abnormal autoimmune response leads to the release of proteins known as antibodies, which damage the thyroid and cause it to produce too much thyroid hormone. The cause of Graves' disease is unknown.

Graves' disease can result in symptoms such as: Unexplained weight loss, often in spite of an increase in appetite Increased sweating and an inability to tolerate heat Increased heart rate Feeling weak and tired Diarrhea or an increase in bowel movements Irregular periods, lighter periods, or infertility Insomnia Excessive swelling in the legs Shaking or trembling Irritated, swollen, or bulging eyes Feeling anxious and nervous

Graves' disease can be treated by several methods, including: Surgery to remove the thyroid gland. Radioactive iodine pills. Anti-thyroid medications. Beta blockers.

Thyroid Disease: The Role of Iodine One potential cause of thyroid problems is getting too much or too little iodine. The thyroid gland needs iodine in order to function and produce the hormones that help regulate the body. If the thyroid gland doesn't get enough iodine, hypothyroidism can result; if there's too much iodine, iodine-induced hyperthyroidism may occur.

Iodine-induced thyroid conditions are the only thyroid diseases that can truly be prevented. In the United States, hypothyroidism due to insufficient iodine is extremely rare because iodized salt is used in many foods, which helps ensure that people get enough iodine through their diet. Ingesting excess iodine from supplements, medication, and food (e.g., seaweed) can lead to iodine-induced hyperthyroidism, so people at risk for this condition should have regular thyroid screenings.

Although iodine-linked thyroid conditions can be prevented, most thyroid disease can't be. For people at risk for thyroid disease, regular screenings and diagnostic tests are the best methods of getting thyroid problems under control quickly.