What is Thyroid Stimulating Hormone (TSH)?
- Published on August 24, 2022
The thyroid stimulating hormone (TSH)- a glycoprotein hormone that is produced by the pituitary gland in the human body, which is positioned at the base of the brain.
Once the hormone is released into the bloodstream, it regulates the production of other thyroid hormones, namely, thyroxine (T4) and triiodothyronine (T3).
Thyroxine has a slight effect on metabolism and is further converted into triiodothyronine, which is majorly responsible for stimulating metabolism.
How is TSH produced, and what is it used for?
The pituitary gland is a small, pea-sized gland that produces and releases eight hormones in total. The pituitary stalk connects the pituitary gland to the hypothalamus.
The hypothalamus is the primary part of the brain that controls bodily functions like digestion, heart rate, blood pressure, etc.
Through the pituitary stalk, the hypothalamus communicates with the pituitary gland, directing how much hormone to produce and release. Based on the feedback, the pituitary gland triggers the release of thyroid stimulating hormones, around 80% of Thyroxine or T4 and 20% of Triiodothyronine or T3.
Once the hormones are released in the bloodstream, through the process of de-iodination, T4 is converted into T3. Cells in the liver, kidneys, muscles, thyroid, and nervous system help convert T4 into T3.
Upon successful conversion, the thyroid stimulating hormones (T4 + T3) aid in several functions of the body, such as:
- Controlling the rate at which the body utilizes calories
- Monitoring the heart rate
- Monitoring the body temperature
- Regulating the way body muscles contract
- Monitoring the cell replacement rate
- Controlling the food movement via the digestive tract
- Monitoring bone health
- Regulating the menstruation cycle in women
- Monitoring growth and development in infants and children
Why do I need a TSH test?
A TSH test measures the amount of thyroid-stimulating hormone in the body. Doctors generally order this test if a person is experiencing a thyroid disorder. Hypothyroidism and hyperthyroidism are the two conditions this test can help diagnose.
In hypothyroidism, there is too less TSH in the body which causes the body’s metabolism to slow down.
Contrastingly, in hyperthyroidism, there is too much thyroid stimulating hormone in the body, causing the metabolism to speed up more than required.
Thyroid disorders have numerous noticeable symptoms like unexplained weight gain or weight loss, a slow or fast heart rate, dry or oily skin, irregular menstrual cycles, intolerance to hold or cold temperatures, frequent bowel movements, and shaky hands, fatigue, etc.
If you are experiencing these symptoms and cannot identify their cause, we recommend consulting a doctor. They might recommend a TSH test to help determine if you have an underactive or overactive thyroid gland condition.
Additionally, a thyroid-stimulating hormone test can also diagnose or rule out other critical conditions like Grave’s disease, thyroid cancer, and Hashimoto’s thyroiditis.
Sometimes a TSH test is also ordered for newborn babies as a precautionary measure. This prompts early diagnosis and provides treatment options.
What happens during a TSH test?
During a TSH test, the healthcare official will simply take your blood sample. The blood sample will then be sent to the laboratory for testing.
You need not follow any specific instructions before or after the test unless your doctor asks you to. You might only be asked to fast for a few hours before the test.
However, some medicines can interfere with the results of the TSH test. Avoid consuming dopamine, lithium, potassium iodide, biotin, amiodarone, and prednisone before the test.
Are there any risks and complications with TSH tests?
There are no risks and complications involved in a TSH test. You might feel a little sting when your blood sample is taken.
In case you are suffering from some other conditions, your health care provider would know your medical history and advise you accordingly.
What are the causes of high TSH levels?
According to the American Thyroid Association, the normal TSH levels in the human body are 04.-4.0 milliunits per litre. Anything in the range of 4 to 5 milliunits per litre and above is considered a high TSH level.
Some of the causes of high TSH levels are:
- Hormonal changes at the time of birth
- Certain medicines and supplements
- Injury to the thyroid gland
- Radiation therapy
- Partial or complete removal of the thyroid gland
- Iodine deficiency
- Excess iodine
- Pituitary tumour
Some of the symptoms of thyroid stimulating hormone high levels are:
- Inflamed thyroid
- Extreme sensitivity to cold
- Unexplained weight gain
- Dry skin
- Thinning hair
- Brittle and weak nails
- Heart ailments
- Muscle pain
- Joint pain
- Excessive snoring
- Thyroid cancer
How are high TSH levels treated?
The treatment of high TSH levels will depend on the exact amount of your hormone level, along with your previous medical history. The doctor will also closely analyze all your signs and symptoms before recommending a treatment plan.
The standard treatment plan includes a synthetic dose of thyroid hormone medication daily. This daily dose will monitor the thyroid hormone levels and reverse the symptoms.
However, bear in mind that this is a gradual process, and you will not see the results immediately after medication. Those suffering from thyroid conditions need to follow a strict daily medication routine and other necessary lifestyle changes.
High TSH levels are a very common occurrence nowadays due to contemporary lifestyle practices and eating habits.
Do not be excessively worried if you are experiencing this condition. Just keep an eye on your symptoms and get medical advice as and when needed.
Many treatment plans and preventive care are available to make it easier for you. To avail the best treatment for fluctuating TSH levels, visit your nearest Birla Fertility and IVF Center or book an appointment with Dr. Rachita Munjal.
1. Will I need to do anything to prepare for the TSH test?
You need not take any specific measures for the thyroid stimulating hormone test. Your doctor might ask you to fast a few hours before getting your blood drawn. Besides that, avoid taking certain drugs like dopamine, lithium, potassium iodide, biotin, amiodarone, and prednisone before the test.
2. What do the TSH test results mean?
The normal level of TSH in the human body is 04.-4.0 milliunits per litre. Anything higher than 4 indicates a high level, and anything less than 1 indicates a low TSH level.
3. What happens when the TSH levels are high?
A person with high TSH levels might experience some symptoms like anxiety, depression, constipation, dry skin, weight gain, attention issues, and extreme sensitivity to cold.
4. What is a normal TSH level in a woman?
The normal TSH range for females can fluctuate during menstruation, menopause, and pregnancy. During these times, it will fall within the range of 0.5 to 2.5 milliunits per litre.
Dr Rachita Munjal
Consultant – Birla Fertility and IVF
Dr Rachita Munjal completed her MBBS from Dr D. Y. Patil Medical College, Hospital & Research Centre, Pune and MS (Obstetrics and gynaecology) from Dr. D.Y Patil Vidyapeeth Pune. She has also completed her DAGE (Diploma in Advanced Gynae Endoscopy) from Germany and MRCOG-I (Royal College of Obstetricians & Gynaecologists, UK) Membership Examination.
Over 14 years of experience
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