You may need this test if you have symptoms of a thyroid disorder, such as fatigue, weight changes, or abnormal heart rate, or if you are being treated for a thyroid condition and need to monitor your hormone levels.

1. TSH (Thyroid-Stimulating Hormone): The primary hormone tested to assess thyroid gland activity.
2. FT4 (Free T4): If TSH is abnormal, FT4 is measured to provide more detail on thyroid hormone levels.

1. Assess Thyroid Function: Determines how well your thyroid gland is working.
2. Diagnose Disorders: Helps diagnose conditions like hypothyroidism (low thyroid hormone levels) or hyperthyroidism (high thyroid hormone levels).
3. Monitor Treatment: Assesses the effectiveness of treatment for thyroid conditions, ensuring appropriate hormone levels are maintained.

To prepare for a TSH test:

1. Follow Medication Instructions: Inform your healthcare provider about any thyroid medications or supplements you’re taking. You may need to adjust your medication or timing for the test.

2. No Special Preparation: Generally, no fasting or special preparation is required for a TSH test.

3. Timing: If instructed, take the test at the same time of day consistently, as TSH levels can vary throughout the day.

Always follow any specific instructions provided by your healthcare provider for the most accurate results.