Endocrinology Tests: Understanding TSH, T3/T4, Insulin, and Cortisol
Endocrinology tests are critical for diagnosing and monitoring conditions related to hormone imbalance. These tests evaluate the function of endocrine glands such as the thyroid, adrenal glands, and pancreas. The most commonly performed endocrine blood tests include TSH, T3/T4, insulin, and cortisol levels. Together, they provide a clear picture of how well your body is producing and regulating hormones.
Why Are Endocrine Tests Important?
Hormones act as chemical messengers in your body. Even slight imbalances can lead to major health issues such as hypothyroidism, hyperthyroidism, diabetes, Cushing’s syndrome, or adrenal fatigue. These tests are often ordered when symptoms like fatigue, weight changes, mood swings, or irregular menstruation arise.
1. TSH (Thyroid Stimulating Hormone)
TSH is a hormone produced by the pituitary gland that regulates the thyroid. It tells the thyroid when to produce T3 (triiodothyronine) and T4 (thyroxine).
High TSH may indicate hypothyroidism (underactive thyroid).
Low TSH can point to hyperthyroidism (overactive thyroid).
TSH levels are crucial for diagnosing thyroid disorders and monitoring treatment with thyroid medication.
Learn more:
🔗 Mayo Clinic – TSH Test
2. T3 and T4 (Thyroid Hormones)
T3 and T4 are the primary hormones released by the thyroid gland. They control your metabolism, energy levels, and even brain function.
Low T3/T4 = Sluggish metabolism, weight gain, depression
High T3/T4 = Rapid heartbeat, anxiety, weight loss
These tests are used alongside TSH to confirm thyroid conditions like Graves’ disease, Hashimoto’s thyroiditis, and others.
Trusted source:
🔗 MedlinePlus – T3 and T4 Tests
3. Insulin
Insulin is a hormone made by the pancreas that regulates blood sugar (glucose) levels. Measuring insulin can help detect:
Insulin resistance (early sign of type 2 diabetes)
Hypoglycemia (low blood sugar)
Pancreatic tumors
It’s a key test in managing metabolic syndrome and pre-diabetes, especially in overweight or sedentary individuals.
Trusted source:
🔗 NIH – Insulin Resistance and Diabetes
4. Cortisol
Cortisol is a steroid hormone made by the adrenal glands. It helps regulate metabolism, blood pressure, and the stress response.
High cortisol may signal Cushing’s syndrome
Low cortisol can indicate Addison’s disease
Cortisol levels typically follow a daily rhythm, so blood, saliva, or urine samples may be timed accordingly.
More information:
🔗 Cleveland Clinic – Cortisol Test
Conclusion
Endocrinology tests like TSH, T3/T4, insulin, and cortisol offer essential insights into hormone function and overall health. They are widely used to diagnose thyroid disorders, metabolic conditions, adrenal diseases, and diabetes. If you’re experiencing unexplained symptoms, your doctor may recommend one or more of these tests to find the root cause.
Understanding these hormone tests empowers you to take a more proactive role in managing your health.
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