Thyroid testing
- 1. TSH
- 2. Your thyroid is a butterfly-shaped gland in your neck, just above your collarbone. It is one of your endocrine glands, which make hormones. Thyroid hormones control the rate of many activities in your body. These include how fast you burn calories and how fast your heart beats. All of these activities are your body's metabolism.
- 3. If your thyroid gland is not active enough, it is called hypothyroidism. It can make you gain weight, feel fatigued, and have difficulty dealing with cold temperatures. If your thyroid is too active, it makes more thyroid hormones than your body needs. That condition is called hyperthyroidism. Too much thyroid hormone can make you lose weight, speed up your heart rate, and make you very sensitive to heat.
- 4. Usually the first blood test performed is the TSH test. TSH is the key hormone for diagnosing hyperthyroidism and hypothyroidism. If results of the TSH test are abnormal, one or more additional tests are needed to help determine the cause of the problem.
- 5. In people whose thyroid produces too much thyroid hormone, the pituitary shuts down TSH production, leading to low or even undetectable TSH levels in the blood. An abnormally low TSH level suggests hyperthyroidism.
- 6. In people whose thyroid is not functioning normally and produces too little thyroid hormone, the thyroid cannot respond normally to TSH by producing thyroid hormone. As a result, the pituitary keeps making TSH, trying to get the thyroid to respond. An abnormally high TSH level suggests hypothyroidism. Watch the video in the next section to increase your understanding of thyroid issues.