TSH is a blood test used to screen for thyroid dysfunction, specifically to evaluate how well the thyroid gland is functioning.
TSH is produced by the pituitary gland in the brain.
It stimulates the thyroid gland (in the neck) to produce thyroid hormones:
T3 (Triiodothyronine)
T4 (Thyroxine)
These hormones control your metabolism, energy levels, body temperature, and more.
Adults: 0.4 – 4.0 mIU/L
(May vary slightly by lab. Some sources consider 0.3–3.0 mIU/L as optimal.)
Indicates hypothyroidism (underactive thyroid)
Common causes:
Hashimoto’s thyroiditis (autoimmune)
Iodine deficiency
Post-thyroid surgery or radiation
Indicates hyperthyroidism (overactive thyroid)
Common causes:
Graves’ disease (autoimmune)
Thyroid nodules or goiter
Too much thyroid hormone medication
It's highly sensitive to small changes in thyroid function.
Often used as the first-line test before checking T3/T4 levels.
Part of routine health checkups, especially:
In women
In people with fatigue, weight changes, or mood issues
During pregnancy or fertility assessments.
TSH is a blood test used to screen for thyroid dysfunction, specifically to evaluate how well the thyroid gland is functioning.
TSH is produced by the pituitary gland in the brain.
It stimulates the thyroid gland (in the neck) to produce thyroid hormones:
T3 (Triiodothyronine)
T4 (Thyroxine)
These hormones control your metabolism, energy levels, body temperature, and more.
Adults: 0.4 – 4.0 mIU/L
(May vary slightly by lab. Some sources consider 0.3–3.0 mIU/L as optimal.)
Indicates hypothyroidism (underactive thyroid)
Common causes:
Hashimoto’s thyroiditis (autoimmune)
Iodine deficiency
Post-thyroid surgery or radiation
Indicates hyperthyroidism (overactive thyroid)
Common causes:
Graves’ disease (autoimmune)
Thyroid nodules or goiter
Too much thyroid hormone medication
It's highly sensitive to small changes in thyroid function.
Often used as the first-line test before checking T3/T4 levels.
Part of routine health checkups, especially:
In women
In people with fatigue, weight changes, or mood issues
During pregnancy or fertility assessments.
The only parameter included in a basic TSH screening.
Evaluates how well your thyroid is being regulated by the pituitary gland.
Helps detect:
Hypothyroidism (high TSH)
Hyperthyroidism (low TSH)
Subclinical thyroid disorders
Blood sample from a vein (usually taken in the morning, fasting not always required).
Results are usually available within 24 hours.
Routine health checkups
Symptoms like fatigue, weight gain/loss, irregular periods, or hair loss
Monitoring thyroid medication
Pregnancy or fertility assessments
Note: The TSH test alone gives a basic picture of thyroid health. If abnormal, doctors may order additional tests like Free T3, Free T4, and Thyroid antibodies (TPOAb, TgAb) for a complete diagnosis.
Test | Purpose / What It Detects |
---|---|
Free T3 (FT3) | Measures the active form of the thyroid hormone T3. Important in diagnosing hyperthyroidism. |
Free T4 (FT4) | Measures active T4 hormone. Helps confirm hypo- or hyperthyroidism along with TSH. |
Total T3 / Total T4 | Measures both bound and unbound forms. Less commonly used today, but still relevant in some cases. |
TPO Antibodies (TPOAb) | Detects autoimmune thyroid disease like Hashimoto’s thyroiditis or Graves’ disease. |
Thyroglobulin Antibodies (TgAb) | Another autoimmune marker, useful in thyroid cancer monitoring or Hashimoto’s disease. |
Reverse T3 (rT3) | Measures inactive thyroid hormone. Used in complex cases (e.g., thyroid hormone resistance). |
Thyroid Ultrasound | Imaging to assess physical structure of the thyroid (nodules, enlargement). |
TSH Receptor Antibodies (TRAb) | Used to diagnose Graves' disease (autoimmune hyperthyroidism). |
A Health Check-Up is a preventive medical examination designed to assess your overall health status and detect early signs of diseases or risk factors. These check-ups typically include a series of physical examinations, laboratory tests, and diagnostic screenings tailored to age, gender, medical history, and lifestyle.
Routine health check-ups are essential for early detection of conditions such as diabetes, heart disease, hypertension, and cancer. They help doctors monitor critical indicators like blood pressure, cholesterol levels, organ function, and more. Depending on the package or provider, a health check-up can range from basic blood tests to advanced imaging like CT scans or full-body MRIs.