How is Congenital Adrenal Hyperplasia (CAH) diagnosed?

Congenital Adrenal Hyperplasia (CAH) is a genetic disorder that affects the adrenal glands, which are responsible for producing hormones that regulate various bodily functions. CAH is typically diagnosed through a combination of clinical evaluation, hormone testing, and genetic testing.

Clinical Evaluation: The first step in diagnosing CAH involves a thorough clinical evaluation by a healthcare professional. They will review the patient's medical history, assess symptoms, and perform a physical examination. CAH may present differently depending on the specific type and severity of the condition.

Hormone Testing: Hormone testing is crucial in diagnosing CAH. It involves measuring the levels of various hormones in the blood or urine. The most commonly measured hormones include:

• 17-hydroxyprogesterone (17-OHP): Elevated levels of 17-OHP are a key indicator of CAH. This hormone is produced in excess in individuals with CAH due to a deficiency in certain enzymes involved in cortisol production.


• Cortisol: Cortisol levels may be low or normal in individuals with CAH, depending on the specific enzyme deficiency. Low cortisol levels can lead to symptoms such as fatigue, weakness, and low blood sugar.


• Aldosterone: Aldosterone levels may also be affected in some forms of CAH. Aldosterone helps regulate blood pressure and electrolyte balance, so abnormalities in its levels can cause salt-wasting and dehydration.


• Androgens: In some cases of CAH, excessive androgen production can lead to ambiguous genitalia in newborn females or early signs of puberty in both males and females.

Genetic Testing: Genetic testing is used to confirm the diagnosis of CAH and identify the specific genetic mutation responsible for the condition. This testing is typically done through a blood sample. It can detect mutations in genes involved in adrenal hormone production, such as the CYP21A2 gene. Genetic testing is particularly useful for identifying carriers of CAH and for prenatal diagnosis.

Imaging Studies: In some cases, imaging studies such as ultrasound or MRI may be performed to evaluate the size and structure of the adrenal glands. These studies can help identify any abnormalities or tumors that may be causing CAH symptoms.

It is important to note that CAH is a complex condition with various forms and degrees of severity. The diagnostic process may vary depending on the specific type of CAH suspected and the age of the individual being evaluated. A multidisciplinary approach involving endocrinologists, geneticists, and other specialists is often necessary to accurately diagnose and manage CAH.