The thyrotropin receptor antibody (TRAb) test is a blood test that helps healthcare providers diagnose the autoimmune thyroid condition called Graves' Disease. The antibodies it tests for are present in between 90% and 100% of the people who have this disease.

Other names for the TRAb test include:

This article will go over the TRAb test, why you may need it, what it looks for, and what to expect during the test.

Your healthcare provider may send you for a TRAb test if you have symptoms that are consistent with hyperthyroidism (an over-active thyroid gland) or Graves' Disease. This is the cause of thyroid over-activity more than 70% of the time hyperthyroidism is diagnosed. These symptoms include:

These are some of the major symptoms, but hyperthyroidism can cause many other symptoms as well.

A few symptoms are associated with Graves' disease but not other forms of hyperthyroidism. Not everyone has them, but when they're present, they make Graves' more highly suspected. They are:

The TRAb test detects the autoantibody that's associated with Graves' disease. An antibody is a specialized protein made by your immune system. Antibodies are custom made to kill pathogens in your body, such as viruses or bacteria.

An autoantibody is a mistake—your immune system has wrongly identified a healthy tissue as a pathogen and seeks to destroy it.

Thyrotropin is also called thyroid-stimulating hormone, or TSH. TSH binds to receptors on the thyroid gland to tell it to produce thyroid hormone. The thyrotropin receptor antibody mimics TSH, so when it's present, it directs the thyroid to keep releasing hormone when your body doesn't need it. That results in high levels of thyroid hormones, which is what causes symptoms. If the thyrotropin receptor antibody is present, it's an indicator of Graves' disease.

Because this autoantibody is only present in 90% of people with Graves', a negative test doesn't automatically rule out the disease. Your healthcare provider will have to rely on the symptoms you report as well as other tests in order to make a diagnosis.

The TRAb test has seen some controversy over how accurate it is. An analysis of research on the subject, though, finds that the science behind the test has come a long way. Now in its third generation, researchers concluded that better testing has provided a springboard for better, individualized treatment.

Along with the TRAb, your healthcare provider may order a number of blood tests to help diagnose you. In someone who has symptoms consistent with hyperthyroidism, those tests are likely to include:

Healthcare providers may also request an ultrasound of the thyroid or a thyroid iodine uptake scan to see if the thyroid gland's appearance has been altered.

Blood tests are common and quite safe. You may feel a sting from the needle. Afterward, you may have a small red mark where the needle was inserted, and sometimes the area can bruise. Keep the injection site clean as you would any cut or scrape.

Simple blood tests like those performed for hyperthyroidism are not associated with any long-term effects.

If you have a bleeding disorder, cellulitis, or problems with your veins, let your healthcare provider know before you go for a blood test.

You shouldn't need to go without food or drink or prepare in any way before your TRAb or other thyroid-hormone tests. These tests can typically be performed at any time of day.

For any blood draw, it's important that you're hydrated—both for your own sake and to make the procedure easier.

A blood draw for a TRAb is sometimes done by a nurse in your healthcare provider's office, but you may be sent to a lab. The test itself takes very little time—just a couple of minutes.

However, when you go in for the test, you may have to fill out forms and/or wait for the lab tech to get to you. If you're concerned about how much time it will take, call the lab to check on wait times or ask what time of day is usually fastest.

If you're anxious about the test, you may want to give yourself extra time in case you suffer negative effects from the anxiety, such as dizziness or a panic attack. You may also want to arrange for someone to drive you to and from the test.

You probably will not get the results of your TRAb right away. It's more likely that your healthcare provider will contact you later with the results. You may want to ask the practitioner how long it should take to hear from them and check with the office if it seems like you've waited too long. Expect it to take at least several days.

Wear short sleeves or sleeves that can easily be pushed or rolled up. You shouldn't need to change into a hospital gown for a TRAb.

Your health insurance may require pre-approval before you get a TRAb test, so check with the company. You may have a copay or be responsible for a portion of the cost. Your healthcare provider's office or the lab should be able to tell you the price before the test.

When you go to be tested, have your insurance card and any paperwork your healthcare provider may have given you regarding the test. You may want to bring something to occupy your time if you expect a long wait.

The test procedure is fairly simple. Here's what to expect.

The nurse or phlebotomist who draws your blood may ask you to confirm your name, birth date, and other information to ensure there's no mix-up and everything is properly labeled.

They'll ask you to push up your sleeve or remove a long-sleeved layer if necessary. Then they'll tie something around your upper arm to trap blood in the vein they're planning to use and swab the site with alcohol to clean it. They may ask you to make a fist or squeeze your hands open and closed.

They'll then insert the needle and release the tourniquet on your arm to encourage blood flow. If multiple tests are being performed on your blood, they may switch out vials one or more times. Once the requisite blood is withdrawn, they'll slip the needle out and put pressure on the site to stop the bleeding.

After that, they'll bandage it and you should be free to go. If you're having any problems, such as anxiety or dizziness, let them know. They may want to monitor you for a while to make sure it's safe for you to leave.

You may have a little soreness around the site, and it may bruise a little, which is normal. The bruise should go away in a few days.

You shouldn't have any other lingering effects from a simple blood draw. If you experience any other adverse effects, call your healthcare provider.

TRAb test results are pretty simple to interpret—if you test positive for the autoantibodies, you likely have Graves' disease. If not, your healthcare provider may do other tests to determine whether you have Graves' or another condition, depending on how your other thyroid hormone levels are.

Once you've received your results, you may need to go back to the healthcare provider to discuss treatment options or for further testing, if results were negative or inconclusive.

The TRAb test is a blood test that helps diagnose the thyroid condition Graves' Disease. It looks for an antibody associated with the condition.

The TRAb test is a simple blood test that does not require fasting. It can typically be done at any time of the day. The test will either be positive or negative for the antibodies. If it's positive, it's likely you have Graves' disease.