What is a TSH(Thyroid-stimulating hormone) test ?
TSH stands for thyroid-stimulating hormone. A TSH test is a blood test that measures this hormone. The thyroid is a small, butterfly-shaped gland located near your throat. Your thyroid makes hormones that regulate the way your body uses energy. It also plays an important role in regulating your weight, body temperature, muscle strength, and even your mood. TSH is made in a gland in the brain called the pituitary. When thyroid levels in your body are low, the pituitary gland makes more TSH. When thyroid levels are high, the pituitary gland makes less TSH. TSH levels that are too high or too low can indicate your thyroid isn't working correctly.
Other names: thyrotropin test
What is it used for ?
A TSH test is used to find out how well the thyroid is working.
Why do I need a TSH test?
You may need a TSH test if you have symptoms of too much thyroid hormone in your blood (hyperthyroidism), or too little thyroid hormone (hypothyroidism).
Symptoms of hyperthyroidism, also known as overactive thyroid, include:
- Weight loss
- Tremors in the hands
- Increased heart rate
- Bulging of the eyes
- Difficulty sleeping
Symptoms of hypothyroidism, also known as underactive thyroid, include:
- Weight gain
- Hair loss
- Low tolerance for cold temperatures
- Irregular menstrual periods
What happens during a TSH test?
A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.
Will I need to do anything to prepare for the test?
You don't need any special preparations for a TSH blood test. If your health care provider has ordered other blood tests, you may need to fast (not eat or drink) for several hours before the test. Your health care provider will let you know if there are any special instructions to follow.
Are there any risks to the test?
There is very little risk to having a blood test. You may have slight pain or bruise at the spot where the needle was put in, but most symptoms go away quickly.