What is the TSH Test?
Your thyroid gland is located near your throat. It is butterfly-like in shape and very small. The thyroid is a very important organ as it produces a hormone that is responsible for the regulation of energy in your body. Additionally, the thyroid works to regulate your mood, muscle strength, body temperature, and weight.
TSH stands for “thyroid stimulating hormone”. It is created in the pituitary gland—which is in the brain. Levels of this hormone may be either high or low and may indicate if your thyroid is functioning properly. When thyroid levels are low, the gland works to produce more TSH and vice versa.
To check its level, a TSH test is done. More specifically, the test measures how much thyroid hormone is in your blood. A high level of TSH may indicate that the thyroid is underactive and you have hypothyroidism. Meanwhile, if TSH levels are low, it may suggest your thyroid is overactive and that you have hyperthyroidism.
Why Do You Need a TSH Test?
If you are showing signs of either hyperthyroidism or hypothyroidism, you should undergo a TSH test.
Hyperthyroidism, also referred to as overactive thyroid, have the following symptoms:
- Sleeping difficulties
- Abnormal fast heart rates
- Bulging of eyes
- Tremors in the hands
- Weight loss
Meanwhile, hypothyroidism, also referred to as underactive thyroid, will show the following symptoms:
- Irregular menstrual periods
- Hair loss
- Weight gain
- Low tolerance for cold temperatures
The TSH Test Process
The TSH test is done by extracting a blood sample, then it will be brought in a lab to be examined. Its results may either show if your thyroid gland is overactive or underactive. In medical terms, they call it hyperthyroidism and hypothyroidism. The test may also detect any existing thyroid problem when you haven’t got any symptoms yet.
Your TSH level is constant in the morning while it can rise or fall throughout the day, thus, TSH test is best to do in the morning. Unlike other tests, TSH test does not require any preparation such as fasting. However, certain medications may interfere with it, so might stop it before the test.
You should not feel any pain during the extraction procedure aside from the small prick in your arm and a slight bruising.
Nevertheless, it is not TSH testing that can only diagnose thyroid disease. Other tests such as the anti-TPO antibody, the reverse T3, the free T3, and the free T4 are used to determine if you need medical attention regarding your thyroid condition.
What Are the Factors That May Affect a TSH Test Result?
Multiple factors can affect your TSH test results. It can be any of the below:
- Laboratory Error – if the result of the TSH test is startling, you should go for another TSH test. Errors are possible, whether it is from transcribing the results, drawing of blood, or getting mix-up in the lab.
- Antibodies – antibodies such as thyroid and heterophile can lead to misdiagnosis. Furthermore, it may cause for inappropriate treatment.
Other factors to affect your TSH result may exist such as:
- Biotin supplements
- Changes in sleep habits
- Medications used for treating cancer and heart disease
- Medications that are non-steroidal and anti-inflammatory
- The testing time: TSH levels vary depending on the time of the day. For instance, it can high in the morning when you are not yet eating anything compared to other time of the day.
Health experts advise being consistent when having your TSH testing. For example, if you did it in the morning before, your next TSH test should be in the morning. By this, your TSH results have the chance to be more accurate.
TSH Test Results
The results of TSH testing have two kinds, a high and low level of TSH. Each of the two has an indication with regards to your health.
High Levels of TSH
Zero-point four to 5 milli-international units per liter (mIU/L) is the normal range of TSH. If the results of your TSH is higher, it means that your thyroid gland is underactive. Nevertheless, pregnant women tend to get a high result when their TSH level is examined. Meanwhile, medications such as dopamine, steroids, or opioid painkillers can make your TSH level lower than normal.
A high TSH may indicate that you have peripheral hypothyroidism, especially if you are not undergoing any treatment. This usually happens when the pituitary gland produces too many TSH because it detects that you have a low level of thyroid hormones. If antibodies are also detected by the pituitary gland, there is a high chance that it will elevate the production of TSH.
On the other hand, if you are undergoing a thyroid disease treatment, your TSH level will most probably be detected high.
Low Levels of TSH
Another result of the TSH test will show that you have low levels of TSH. This indicates that you have an overactive thyroid gland. An overactive thyroid gland may indicate that you have:
- Excessive thyroid hormone medication
- Excessive natural thyroid-hormone-containing supplement
- Excessive iodine in the body
- Severe illness as your immune system attacks the thyroid
Having an overactive thyroid gland may also indicate that you need further treatment to reduce the level of thyroid hormone.
Nevertheless, a low level of TSH could not always mean hyperthyroidism. It could also indicate central hypothyroidism. Central hypothyroidism is less common as it usually associated with pituitary hormones deficiency.
If you are receiving treatment for hypothyroidism and your TSH test result is low, it could mean that:
- You have central hypothyroidism
- You are overmedicated with thyroid hormone replacement
- Your medication dose is perfect, however, interference occurred that accelerate the activity or absorption
How to Treat Thyroid Issues?
Underactive thyroids can be treated through medication. The pill is consists of a synthetic thyroid hormone and it pulls hormone level down and makes it normal. In a few days, you may lose weight and feel less exhausted.
To check if you are taking the right dosage, your doctor will conduct another TSH test after 2 to 3 months. If it is confirmed that you are taking the right dosage, your doctor will advise you to continue. Moreover, he or she will check your TSH level annually to make sure it is normal.