How to Detect Hyperthyroidism in Children: Symptoms, Testing, and Diagnosis

When hyperthyroidism is suspected in a child, healthcare providers typically begin with a comprehensive evaluation to confirm the diagnosis. Early detection is crucial for effective management and preventing complications. The diagnostic process involves several key steps, including blood tests, imaging studies, and sometimes specialized functional assessments.

Common Diagnostic Tests for Pediatric Hyperthyroidism

Blood Tests: Assessing Hormone and Antibody Levels

One of the first steps in diagnosing childhood hyperthyroidism is a blood test to measure thyroid hormone levels. This includes checking levels of thyroxine (T4), triiodothyronine (T3), and thyroid-stimulating hormone (TSH). In cases of hyperthyroidism, T3 and T4 are often elevated, while TSH is suppressed. Additionally, doctors may order tests for thyroid antibodies—such as thyroid peroxidase antibodies (TPO) and TSH receptor antibodies (TRAb)—to determine if an autoimmune condition like Graves' disease is the underlying cause.

Thyroid Ultrasound: Evaluating Gland Structure

A thyroid ultrasound uses sound waves to create detailed images of the thyroid gland. This non-invasive procedure helps assess the size, shape, and texture of the thyroid. It can reveal whether the gland is enlarged (goiter) or contains nodules that might be contributing to overactivity. While ultrasound alone cannot confirm hyperthyroidism, it provides valuable structural information that supports further testing.

Nuclear Medicine Scans: Measuring Thyroid Function

In certain cases, a radioactive iodine uptake (RAIU) test or a thyroid scan may be recommended. These nuclear medicine procedures evaluate how actively the thyroid gland is producing hormones. During the RAIU test, the child ingests a small amount of radioactive iodine, and a special camera measures how much is absorbed by the thyroid. High uptake indicates increased activity, which is typical in conditions like Graves' disease. This test helps differentiate between various causes of hyperthyroidism.

Cardiac Evaluations: Monitoring Heart Health

Because excess thyroid hormones can affect the cardiovascular system, children showing symptoms such as palpitations, chest tightness, or rapid heartbeat may require cardiac testing. An electrocardiogram (ECG or EKG) checks for abnormal heart rhythms, while an echocardiogram (cardiac ultrasound) evaluates heart structure and function. These tests help rule out other potential causes of symptoms and ensure safe treatment planning.

Recognizing the Warning Signs in Kids

Parents should be alert to common signs of hyperthyroidism in children, which may include unexplained weight loss despite increased appetite, excessive thirst and urination, nervousness, irritability, mood swings, difficulty concentrating, heat intolerance, tremors, and visible swelling in the neck (enlarged thyroid). Some children may also experience fatigue, trouble sleeping, or changes in academic performance due to restlessness and anxiety.

If any of these symptoms persist, it's important to seek care from a pediatric endocrinologist—a specialist in childhood hormonal disorders. Early consultation allows for timely testing and intervention, minimizing long-term effects on growth, development, and overall well-being.