Congenital adrenal hyperplasia (CAH) refers to a group of congenital (present at birth) conditions caused by problems with the adrenal glands.

Typically, a person has two adrenal glands, one on top of each kidney. These glands are responsible for making hormones, including cortisol. Cortisol is important for maintaining proper blood pressure, blood sugar, and energy levels. It is also called the “stress hormone” because it produces the “fight-or-flight” feeling people get during times of stress.

In order to make cortisol, the adrenal glands need certain enzymes. Because of a genetic problem, people with CAH are unable to make one or more of these enzymes. As a result, the body produces more androgens – male sex hormones.

There are two types of CAH. One is more severe than the other.

• In children with classical CAH, excess androgen production begins while they are still in the womb. As a result, girls with CAH are sometimes born with ambiguous genitalia, with an enlarged clitoris that might resemble a penis. CAH is more difficult to detect in boys at first, although the penis might be larger than normal. As children with classical CAH get older, they might go through puberty earlier than their peers. They often grow quickly, but end up being shorter-than-average adults. Girls may have irregular menstrual periods.
  Classical CAH can be life-threatening. If not caught early and treated correctly, patients may experience an adrenal crisis – dehydration, vomiting, diarrhea, low blood sugar, low sodium levels, and shock. Adrenal crisis is an emergency.

Treatment of classical CAH usually involves lifetime medication to balance hormone levels. Reconstructive surgery of the genitals is an option for girls with classical CAH. This may involve reducing the size of the clitoris and repairing the vagina. Surgery is usually done during infancy, but some parents decide to wait until the girl is older.

• Nonclassical CAH is a milder form. These patients can still produce some of the enzymes they need, so the cortisol deficiency and androgen effects are not as severe. Girls with this form generally do not have ambiguous genitalia and patients are not at risk for adrenal crisis. Symptoms of nonclassical CAH often don’t appear until adolescence. Puberty may begin early, with severe acne and excess body hair. Girls’ menstrual periods may be irregular. Nonclassical CAH is generally treated with medication.

Patients with either form of CAH have a normal life expectancy, as long as they take care of themselves and take their medications properly. However, both men and women may have trouble with fertility. Women may have sexual issues, especially if they had genital surgery when they were young.