Step 1: The Blood Tests

The diagnosis begins with four core blood tests:

1. TSH (Thyroid-Stimulating Hormone)

2. Free T4 (Thyroxine)

3. Free T3 (Triiodothyronine)

4. TSH Receptor Antibodies (TRAb)

What These Results Mean

High T3/T4 + Low TSH = Hyperthyroidism

This combination is usually clear-cut.

Sometimes, T3 is elevated before T4 — known as "T3 toxicosis."

If antibodies are positive, the diagnosis is Graves' disease, the most common cause in children.

Step 2: Clinical Examination

During the consultation, I assess:

Heart and Vital Signs

A very fast resting heartbeat is often the first physical clue.

Thyroid Gland

I examine the neck for:

Eyes

In Graves' disease, some children develop:

Severe eye disease is rare in children but important to detect early.

Growth Pattern

Rapid height gain with early bone maturation can suggest prolonged hyperthyroidism.

Step 3: Growth Chart & Bone Age

The growth chart is often a key diagnostic tool.

Children with hyperthyroidism typically:

This means they grow faster now but may stop growing sooner.

The bone age X-ray (left hand/wrist) helps determine whether the child's growth window has shortened.

Step 4: Ultrasound

A thyroid ultrasound is helpful when:

In Graves' disease, ultrasound often shows:

Step 5: Additional Tests

Sometimes used in select cases:

How Quickly Will You Get Answers?

Most blood test results return within 24–72 hours.

With a clear combination of:

The diagnosis becomes definite.

What Happens After Diagnosis?

Treatment begins promptly to:

The next blog post (Post 7) will explain treatment options in detail.