Description

The Thyroid Basic Blood Panel evaluates essential markers of thyroid function: TSH, Free T4, and T3 Uptake. These tests help determine if your thyroid is underactive (hypothyroidism), overactive (hyperthyroidism), or functioning normally.

When thyroid function is abnormal, these values are often the first to show changes:

  • TSH increases when thyroid function is low
  • TSH decreases when thyroid function is high
  • Free T4 reflects the amount of hormone the thyroid produces
  • T3 Uptake helps assess hormone availability and binding activity

This is a basic screening panel. More comprehensive thyroid tests are available for in-depth evaluation.

TSH (Thyroid Stimulating Hormone)

Function: Signals the thyroid to produce hormones

What It Indicates:

  • High TSH → Possible hypothyroidism (underactive thyroid)
  • Low TSH → Possible hyperthyroidism (overactive thyroid)

Free T4 (Free Thyroxine)

Function: Primary hormone produced by the thyroid

What It Indicates:

  • Measures the “free” (active) form of T4 circulating in the blood
  • Low levels may suggest hypothyroidism
  • Helps determine how well the thyroid is functioning

T3 Uptake

Function: Evaluates hormone transport and binding

What It Indicates:

  • Estimates the availability of thyroid hormones
  • Assists in interpreting thyroid function in combination with T4 and TSH

Recommended For

  • General thyroid health screening
  • Fatigue, weight changes, or temperature sensitivity
  • Irregular menstrual cycles or mood changes
  • Baseline testing before starting medications
  • Ongoing thyroid monitoring

Preparation

  • No fasting required
  • Stay hydrated
  • Continue medications unless advised otherwise