1. What is Thyroid Function Testing?

Thyroid function testing measures the levels of thyroid hormones (T3 and T4) and thyroid-stimulating hormone (TSH) in the blood. These tests help evaluate how well your thyroid gland is working and diagnose thyroid disorders.

2. How Does the Calculator Work?

The calculator evaluates your T3, T4, and TSH levels against standard reference ranges:

The calculator compares your values to these reference ranges and provides an interpretation of your thyroid function.

3. Importance of Thyroid Testing

Details: Thyroid hormones regulate metabolism, energy generation, and many other vital bodily functions. Abnormal levels can indicate conditions like hypothyroidism, hyperthyroidism, or other thyroid disorders that require medical attention.

4. Using the Calculator

Tips: Enter your T3 value in ng/dL, T4 value in μg/dL, and TSH value in mIU/L. These values should come from your recent blood test results. All values must be greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: What do T3, T4, and TSH measure?
A: T3 and T4 are thyroid hormones produced by the thyroid gland. TSH is produced by the pituitary gland and stimulates the thyroid to produce T3 and T4.

Q2: What is a normal TSH level?
A: Normal TSH levels typically range from 0.4 to 4.0 mIU/L, though this can vary slightly between laboratories.

Q3: What causes high TSH levels?
A: High TSH usually indicates an underactive thyroid (hypothyroidism), where the pituitary gland produces more TSH to stimulate the thyroid.

Q4: What does low TSH with high T3/T4 indicate?
A: This pattern typically suggests hyperthyroidism (overactive thyroid), where high thyroid hormone levels suppress TSH production.

Q5: Should I fast before thyroid testing?
A: While not always required, some doctors recommend fasting before thyroid tests as food can affect results. Follow your healthcare provider's instructions.