Pediatric Endocrinology Tests and Diagnosis

If your child has symptoms that affect the endocrine system, we use tests to diagnose or rule out endocrine conditions. We also use endocrinology tests throughout treatment to evaluate the effectiveness of a treatment plan. At Children’s Hospital Los Angeles, we use a comprehensive range of endocrinology tests.

Diagnostic Tests for the Endocrine System

Pediatric endocrinologists use several tests to evaluate hormones and diagnose endocrine disorders. Your child may have:

Blood Tests

Blood tests can help us diagnose endocrine conditions. They can also tell us if a treatment plan is working. For example, if your child has hypothyroidism (produces too little thyroid hormones), a blood test allows us to check your child’s thyroid hormone levels. We may also use blood tests during a congenital adrenal hyperplasia (CAH) diagnosis. 

Blood tests are usually quick outpatient tests, meaning your child goes home the same day. During a blood test, a nurse or phlebotomist inserts a needle into your child’s vein and draws a small vial of blood.

CT Scans

A CT scan uses a series of X-rays to create 3D images of your child’s body. We may use CT scans if we suspect that your child has a thyroid tumor (irregular mass on the thyroid) or to diagnose a bone disorder.

During a CT scan, your child lies on a table that slides into the CT machine. The machine looks like a long tunnel open at both ends. A technician takes X-ray images and a computer puts those images together into one detailed, 3D image.


MRIs use radio waves and magnets to create 2D or 3D images of your child’s body. We may use an MRI to look at the thyroid gland or pituitary gland (gland at the base of the brain that produces hormones), or to view a tumor.

During an MRI, your child lies on a table that slides into the MRI machine. The machine is like a long tunnel open at both ends. A technician takes images and a special computer pieces the images together into one 2D or 3D picture.

PET Scans

PET scans can show us the exact location of a tumor. We may use a PET scan if we suspect your child has an irregular growth in the endocrine cells (neuroendocrine tumor). We may also use PET scans to identify tumors on or near the thyroid.

PET scans use injections and special computers to create a detailed image of the inside of the body. During a PET scan, your child receives a safe injection of a radioactive substance. This substance gathers in parts of the body where there are high levels of chemical activity, such as in a tumor. The substance shows up as bright spots on the scan, pinpointing the tumor location.

Stimulation Tests

Stimulation tests evaluate how specific glands in your child’s endocrine system respond to specific hormones. We may use stimulation tests to identify or rule out diabetes, growth hormone problems, early puberty or congenital adrenal hyperplasia.


Ultrasounds use sound waves to create images of your child’s internal body structures. We may use an ultrasound to diagnose thyroid nodules, enlarged thyroid glands or problems with the lymph nodes (small clusters of cells that help the body fight infection).

During an ultrasound, your child’s provider applies a special gel to the skin where your child needs evaluation. Then, the provider moves a wand-like device (transducer) over the area to send out sound waves.

Diagnostic Thyroid Tests

If your child has a thyroid nodule (irregular growth) we may use certain tests to find out whether or not the nodules are cancerous. One common test is a needle aspiration biopsy.

With a needle aspiration biopsy, we take a small sample of cells from the thyroid nodule. Evaluating these cells can tell us whether or not a thyroid nodule is benign (noncancerous). We often use needle aspiration biopsies to identify if your child needs thyroid surgery or additional treatment for nodules.

Diagnostic Tests for Bone Disorders

We may also use specific tests to diagnose bone disorders. Children with conditions that affect their bones may also have:


X-rays use low radiation doses to take images of your child’s internal body structures. Bone calcium absorbs radiation more easily than soft tissues or muscles. That’s why bones appear white on X-ray images. 

Bone Mineral Density Tests

Bone density tests use X-rays to evaluate the mineral density in your child’s bones. Mineral density tells us how strong or breakable your child’s bones are. If your child has low mineral density, the bones may be porous, or more likely to fracture. The steps of a bone mineral density test are similar to any other X-ray.

Urine Tests

We may use urine tests throughout treatment to evaluate how your child’s body is responding. Analyzing a urine sample may tell us if your child has certain chemicals in the blood and how the kidneys are working. We also may look at a urine sample to assess how well your child’s body breaks down bone tissue and adds new bone growth (resorption and ossification).

Endocrinology Diagnosis and Treatment

Our specialists provide a comprehensive range of treatments for endocrine disorders. Many of our doctors have subspecializations, leading to even more targeted, advanced care for your child. Learn more about endocrinology diagnosis and treatment.