Biomarkers

Thyroid Stimulating Hormone

TSH (thyroid stimulating hormone) regulates the production of thyroid hormones, thereby influencing metabolism and energy levels. Abnormal TSH levels may indicate thyroid disorders, such as hypothyroidism or hyperthyroidism, underlining the importance of regular monitoring.

What is TSH?

TSH (thyroid-stimulating hormone) is an essential hormone produced by the pituitary, a small gland located at the base of the brain. Its main function is to regulate the thyroid gland, which controls metabolism, energy levels, and overall body growth.

When the thyroid is working properly, it produces two key hormones:

  • T3 (triiodothyronine)
  • T4 (thyroxine)

These hormones influence almost every cell in the body, helping to regulate energy consumption, body temperature, and the proper functioning of organs.

TSH acts as a messenger between the pituitary and the thyroid. When the body needs more thyroid hormones, the pituitary releases more TSH. Conversely, if levels are high, the pituitary reduces TSH production.

How are TSH levels measured?

TSH levels are usually measured using a simple blood test. This test is often part of larger assessments such as a Thyroid check Or a Hormonal panel.

TSH Test Preparations:

  • Fasting : It is not necessary to fast for a TSH test unless other tests require it.
  • Timing : For women, the timing of the test can be important, especially if there are fertility or menstrual cycle problems. The test is often done on the third day of the menstrual cycle to assess reproductive health.

Normal TSH levels

Normal TSH levels vary by age, gender, and certain conditions such as pregnancy.

Normal ranges by age group:

  • Infants (< 5 days) : 0.7—5.2 IU/ml
  • Infants (6—90 days) : 0.72—11.0 IU/ml
  • Children (4—12 months) : 0.73—8.35 IU/ml
  • Children (1—6 years old) : 0.7—5.97 IU/ml
  • Children (7—11 years old) : 0.6—4.84 IU/ml
  • Teens (12—20 years) : 0.51—4.3 IU/ml
  • Adults (> 21 years) : 0.27—4.2 IU/ml

TSH during pregnancy:

  • 1st quarter : 0.18—2.99 IU/ml
  • 2nd quarter : 0.11—3.98 IU/ml
  • 3rd quarter : 0.48—4.71 IU/ml

Note: The ranges may vary slightly between laboratories.

What do abnormal TSH levels mean?

High TSH Levels (Hypothyroidism)

Hypothyroidism occurs when the thyroid does not produce enough hormones. This causes the pituitary to increase TSH production to compensate.

Hypothyroidism symptoms:
  • Tiredness.
  • Weight gain.
  • Cold intolerance.
  • Dry skin.
  • Hair loss.
Common causes:
  • Hashimoto's disease : An autoimmune disorder that attacks the thyroid.
  • Thyroiditis : Inflammation of the thyroid.
  • Iodine deficiency : Iodine is essential for the production of thyroid hormones.

Low TSH levels (Hyperthyroidism)

Hyperthyroidism occurs when the thyroid produces too many hormones, which suppresses TSH production.

Hyperthyroidism symptoms:
  • Fast heart rate.
  • Weight loss.
  • Nervousness.
  • Tremors.
  • Excessive sweating.
Common causes:
  • Basedow's disease (Graves) : An autoimmune disorder that excessively stimulates the thyroid.
  • Thyroid nodules : Hyperactive areas of the thyroid.
  • Excess iodine : Through food or certain medications.

Factors Affecting TSH Levels

  • Age : TSH levels increase with age.
  • Diseases : Acute or chronic illnesses may temporarily affect levels.
  • Pregnancy : Hormonal changes often reduce TSH, especially in the first trimester.
  • Medications : Some treatments (steroids, dopamine agonists) change TSH.
  • Lifestyle :
    • Iodine intake : Deficiency or excess can alter levels.
    • Stress : Affects the hypothalamic-pituitary-thyroid axis.
    • Sleep : Sleep disorders disrupt hormonal regulation.
  • Managing Abnormal TSH Levels

    Hypothyroidism Treatment:

    1. Hormone replacement therapy : Taking levothyroxine to restore normal hormonal levels.
    2. Diet : Ensure adequate iodine and selenium intake.

    Hyperthyroidism Treatment:

    1. Antithyroid medications : Reduce hormonal production.
    2. Radioactive iodine therapy : Destroys overactive thyroid cells.
    3. Surgery : Partial or total removal of the thyroid in case of serious problems.

    When to See a Doctor?

    If your TSH levels are abnormal or if you have symptoms related to thyroid dysfunction, consult a health professional.

    Specialists to consult:

    • Endocrinologist : Specialized in hormonal and thyroid disorders.
    • Gynecologist : If thyroid problems affect fertility or pregnancy.
    • General practitioner : For regular follow-up or mild symptoms.

    Regularly monitoring TSH levels is essential for maintaining hormonal balance, preventing complications, and improving quality of life.