- Thyroid problems
TSH and thyroid function
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The level of TSH in your blood is an indicator of how well your thyroid is working. If these values are abnormal, this may be a sign of a thyroid problem. Blood tests to measure low or high TSH levels is therefore a first step in diagnosing thyroid problems.
TSH stands for thyroid stimulating hormone and is produced by the pea-sized pituitary gland, located at the base of your brain. TSH causes the thyroid gland to produce hormones that regulate the body's metabolic rate, growth and development.
How can you tell if you have TSH problems?
Problems with TSH production can show up in various forms. Both TSH levels that are too high or too low may be a sign of a thyroid problem.
Symptoms of high TSH levels (hypothyroidism):
- Tiredness
- Weight gain
- Being sensitive to cold
- Dry skin
- Low mood
Symptoms of low TSH levels (hyperthyroidism):
- Weight loss
- Palpitations (rapid heartbeat)
- Nervousness
- Excessive sweating
- Difficulty sleeping
If you are experiencing these symptoms, it’s important to see your doctor for a blood test.
The relationship between TSH and thyroid hormones
The thyroid gland and pituitary gland work together to make surethat there is the right amount of thyroid hormones in the body. TSH stimulates the thyroid gland to make hormones. When hormone concentrations are high, the pituitary gland stops making TSH. When hormone concentrations are low, the pituitary gland makes more TSH.
What are normal and abnormal TSH values?
TSH can vary during the day, but for most people, the normal range falls between 0.4 and 4.0 milliunits per litre (mU/L). If your TSH does not fall within this range, this may be a sign of a thyroid problem.
- Low TSH levels: A low TSH often means a person has an overactive thyroid and an elevated level of thyroid hormones. Weight loss, nervousness and sleep problems are common signs of low TSH.
- High TSH levels: A high TSH often means a person has an underactive thyroid, meaning it is not producing enough essential hormones. Tiredness, weight gain and dry skin are common signs of high TSH.
Diagnostic procedures and interpreting measurements
Measuring the levels of various hormones is often the first thing that doctors do to understand how your thyroid is functioning. A blood test is used to check your thyroid stimulating hormone (TSH), thyroxine (free T4) and triiodothyronine (free T3) blood levels. Together, these measurements give a more complete picture of how your thyroid is working.
- A low T4 level and a high TSH level: This could mean you have an underactive thyroid: your thyroid doesn't make enough hormones even though the pituitary gland is working very hard. This condition is known as primary hypothyroidism.
- A high T4 level and a low TSH level: This indicates that your thyroid makes too much hormones. In this situation, the pituitary gland makes an insufficient amount of TSH because the levels of thyroid hormones in the blood are high. This condition is known as hyperthyroidism.
Although free T3 also plays an important role, the free T3 test is not a first-line test. Measuring free T3 is especially useful in specific thyroid disorders, where T4 and TSH levels alone do not provide enough information. Measuring and understanding the different hormone levels allows your doctor to get a better idea of how your thyroid is functioning and establish if you have hypothyroidism or hyperthyroidism. This allows them to decide upon a treatment plan and monitor its effectiveness.
What causes fluctuations in TSH levels?
There may be various reasons why your TSH levels are fluctuating.
- Autoimmune diseases: Hashimoto’s disease and Graves’ disease can affect the thyroid gland.
- Iodine deficiency: Iodine deficiency results in inadequate production of thyroid hormones.
- Thyroid nodules: These nodules can affect how the thyroid gland works.
- Pregnancy: The surge of pregnancy hormones can cause your TSH levels to fluctuate.
- Medication: Some medications can affect TSH production.
Treating thyroid gland disorders
Treatment for thyroid disorders depends on the type of condition and the severity of the condition. Possible treatment options include:
- Medication: Medications used for the treatment of an underactive thyroid include levothyroxine. Anti-thyroid drugs are commonly used for an overactive thyroid.
- Radioactive iodine: Radioactive iodine therapy is used to treat hyperthyroidism (overactive thyroid gland).
- Surgery: For cancer of the thyroid gland or large nodules.
- Lifestyle changes: A healthy diet and regular exercise can help improve thyroid function.
Conclusion
Your TSH levels are important to understand how well your thyroid is working and to detect any problems. Regular TSH, free T4 and free T3 screening allows you to get a complete picture of your thyroid health. For a correct diagnosis and effective treatment of thyroid problems, it is essential that a doctor carefully considers these values, taking both physical and psychological factors into account.