What is a TSH w/ Reflex, Free T4 test?

Free thyroxine (free T4) tests are used to help evaluate thyroid function and diagnose thyroid diseases, including and hypothyroidism, usually after discovering that the thyroid stimulating hormone (TSH) level is abnormal.

Who should get this test?

A free T4 test may be ordered when a person has symptoms of hyperthyroidism or hypothyroidism, particularly if the TSH test is out of range. Signs and symptoms of hyperthyroidism may include:

  • Increased heart rate
  • Anxiety
  • Weight loss
  • Difficulty sleeping
  • Tremors in the hands
  • Weakness
  • Diarrhea (sometimes)
  • Light sensitivity, visual disturbances
  • The eyes may be affected: puffiness around the eyes, dryness, irritation, and, in some cases, bulging of the eyes.

Symptoms of hypothyroidism may include:

  • Weight gain
  • Dry skin
  • Constipation
  • Cold intolerance
  • Puffy skin
  • Hair loss
  • Fatigue
  • Menstrual irregularity in women
  • Enlarged thyroid gland (goiter)

When will I receive my results?

Once completed, you will receive your results within 3-5 business days in your LabFinder portal.

How do I prepare? Do I need to fast?

No preparation or fasting required. Just bring your LabFinder Order and Insurance Card to your appointment.

Book a TSH w/ Reflex, Free T4
This is for educational purposes only. LabFinder does not provide medical advice, diagnosis or treatment. All users should consult with a medical provider in person for any health concerns.
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How it Works

  • Select your test & location
  • Visit your appointment
  • Access your results
How It Works