What Is Nonclassical Congenital Adrenal Hyperplasia?

Medically Reviewed by Dan Brennan, MD on February 12, 2024
3 min read

Nonclassical congenital adrenal hyperplasia (NCAH) can lead to the production of excess male hormones. It is usually a mild condition and often doesn’t need to be treated. 

Nonclassical congenital adrenal hyperplasia (NCAH) is an inherited disease that affects the adrenal glands and is present at birth.

The adrenal glands are small kidney-shaped glands that sit on top of your kidneys. They produce hormones like cortisol in response to injury; adolsterone, which regulates salt and water levels; and androgens, including male sex hormones. 

If you were born with nonclassical congenital adrenal hyperplasia, your body doesn’t make enough of a certain enzyme called 21-hydroxylase, which affects the amount of hormones your body makes -- often not enough cortisol and too much androgen.

The most common cause of NCAH is 21-hydroxylase deficiency. This enzyme deficiency happens because of a genetic change you inherit. Without enough 21-hydroxylase, the compounds that make cortisol and the hormone aldosterone, build up in your adrenal glands. Your adrenals convert these to androgens, which leads to problems. 

‌NCAH often shows up later in life and isn’t life-threatening. You’re likely to have normal genitals but extra male hormones. 

Lots of people don’t have any NCAH symptoms, or they are mild. Symptoms often look like other conditions, so it can be hard to diagnose. It is sometimes confused with polycystic ovary syndrome, or PCOS, where the ovaries make too many androgen hormones.

NCAH symptoms include:

Your doctor will test for hormone levels in the blood.

If symptoms show up later in life, your doctor might conduct blood tests to check your adrenal steroid levels. You might also take an adrenocorticotropic hormone (ACTH) stimulation test. This is where your doctor tests your cortisol levels and then gives you a dose of ACTH. After an hour, they check your blood levels again. 

In normal test results, cortisol levels are high in response to the hormone. With NCAH, tests show high amounts of the compounds that make cortisol but low levels of cortisol. This means your adrenal system is having trouble making hormones.

Nonclassical congenital adrenal hyperplasia treatment usually isn’t necessary for most people, especially if you don’t have any symptoms. Your doctor might give you medication if you have symptoms like acne, period problems, extra facial hair, or hair loss. These treatments can include:

Unlike the other types of CAH, you might not need to be on medications long-term and can taper off them as your symptoms improve. This should be done under your doctor’s supervision, though.