The thyroid stimulating hormone [TSH] blood test is used to determine the current status of a patient’s pituitary gland, which may also affect the thyroid gland’s health. It is often ordered when there is a suspicion of either hyperthyroidism or hypothyroidism. Located behind the sinus cavities, just below the brain, this gland operates as the feedback system for the body. By producing hormones, it can control the rate at which energy is consumed by the body.
The thyroid stimulating hormone blood test is often ordered with other thyroid tests, such as the T4 test or the T3 test, to look at the complete health picture of the pituitary gland. If an autoimmune disorder is suspected, a thyroid antibody test may also be ordered.
When is the TSH Blood Test Ordered?
There are several reasons why a doctor may order the thyroid stimulating hormone blood test. Newborns are almost always screened with this test to determine if they have an underactive thyroid. Replacement therapies and other thyroid treatments are monitored by this blood test and it can be used to track and diagnose infertility concerns in women.
It will often be ordered because of the bothersome signs and symptoms that a patient may be experiencing. This may include unexpected weight loss, an increased heart rate, higher than normal anxiety levels, trouble sleeping at night, tremors in the hands, feelings of weakness, and light disturbances. These are all possible signs of hyperthyroidism.
The test will also be ordered if the bothersome signs and symptoms of hypothyroidism are being experienced. This may include unintended weight gain, constipation, dry and/or puffy skin, hair loss, an intolerance to cold temperatures, and ongoing fatigue. Women suffering from hyperthyroidism may also experience menstrual cycle irregularities.
What Do the Thyroid Stimulating Hormone Blood Test Results Mean?
TSH results are often communicated in one of three areas: low, normal, or high. Most people who have the TSH test performed will have their results fall into the “normal” area.
If there is a high TSH result, then this means that the thyroid gland is not responding as it should. This may indicate either an acute or chronic gland disorder. People who have had their thyroid gland removed will have a high result if their medication dose needs to be adjusted. An issue with the pituitary gland, such as a tumor on it, can also create high results.
If there is a low TSH result, then this is an indication that a person has an overactive thyroid gland. It may also mean that there is an excessive amount of thyroid hormone medication being taken or an insufficient amount of anti-thyroid medication being administered. A pituitary gland that has been damaged in such a way that it cannot produce adequate amounts of TSH will also produce low overall results.
Whether the TSH blood test results come back low or high, a medical provider will work to create a treatment plan which will begin to stabilize hormone levels so the bothersome symptoms being experienced can be stopped.
Here’s What You Should Know About TSH Testing
There are a number of issues which can affect the overall results of a thyroid stimulating hormone blood test. This includes any changes to the number of proteins that are used to bind the hormones in the bloodstream, whether inherited or acquired by nature.
Women who are pregnant will see changes to their TSH results as well. Low results are often seen during the first trimester of a pregnancy.
A systemic illness is the most common cause of TSH changes. Because of this, the ordering of the thyroid stimulating blood test will often be delayed for anyone who is feeling ill or has been hospitalized until the blood draw can be safely performed during an outpatient visit.
Estrogen is another common cause of TSH changes, as are birth control pills. Individuals suffering from liver disease will also see abnormal levels. Even extreme stress is known to cause TSH changes.
By understanding how much TSH is in a person’s test sample, a medical provider can begin to form a diagnosis involving the bothersome signs and symptoms that may be experienced. By comparing the results to a patient’s medical history, the goal is to correct the issue which is causing abnormal hormone levels to appear.
Some issues may resolve on their own, but if they do not, then it is important to schedule an appointment right away with your doctor to discuss this information with them.