Congenital Adrenal Hyperplasia

September 2017 

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Fady Hannah-Shmouni, MD FRCPC

Additional Resources
National Adrenal Diseases Foundation
The CARES Foundation
The MAGIC Foundation
Mayo Clinic

What is congenital adrenal hyperplasia (CAH)?

Congenital adrenal hyperplasia, also called CAH, is a genetic disorder in which the two adrenal glands do not function properly. Children inherit two abnormal copies of the gene from each of their parents. The adrenal glands, located on top of each kidney, make important hormones, such as cortisol, that are essential for body functions.

The genetic defect in CAH leads to abnormal enzyme (a protein that causes a chemical change in the body) activity in the adrenal glands that are needed for proper function. Without the enzyme, the adrenal glands may produce too little (or nothing) of the hormones cortisol and/or aldosterone and too much androgen. CAH can be severe (classic) or mild (nonclassic).

How is CAH diagnosed?

In the United States and many other countries, newborns are screened for CAH with a blood test from a heel prick right after birth (referred to as newborn screening). Diagnosis in infancy or later also may include:

  • A physical examination
  • Blood tests
  • Genetic test

Sometimes, when there is a known family history of CAH, a fetus is diagnosed before birth. Prenatal treatment of CAH is experimental, and experts recommend it be done only in the context of a clinical trial (a research study that involves people).

What are the different types of CAH?

There are two types of CAH—classic, which can be life-threatening, and nonclassic, a milder form of the disorder.

Classic CAH

Classic CAH, usually first found in infancy or early childhood, is the most severe type. In one form of classic CAH, called “salt-wasting” (meaning the body has trouble keeping the right amount of salt in the blood), the adrenal glands do not make enough cortisol and aldosterone. If not found and treated, classic CAH can cause shock, coma, and death. In another form of classic CAH, called “non-salt wasting,” the enzyme shortage is less severe.

Signs and symptoms

In many cases, female infants are diagnosed at birth, because they have ambiguous genitalia (external sex organs that resemble male genitals). However, they still have normal internal female organs (ovaries and uterus).

A male infant with classic CAH usually appears normal at birth, although he may have an enlarged penis. After infancy, boys with classic CAH grow rapidly and show signs of early puberty.

If infants are not diagnosed at birth, they may show weight loss, dehydration, diarrhea, and heart problems. They also may vomit frequently.


The goals of treatment are to ensure proper hormone levels and promote normal growth and sexual development. Patients with classic CAH should have a team of health care providers, including specialists in pediatric endocrinology, pediatric urologic surgery, mental health care provider, and genetics.

Individuals with classic CAH are treated with a medication called glucocorticoids to replace the cortisol their bodies can't make. Extra glucocorticoids may be needed during times of stress, such as when a patient is sick with an infection. Individuals with classic CAH, especially those with the salt-wasting form, also need medicines called mineralocorticoids. Newborns also may need sodium chloride (salt) supplements.

Surgery can correct ambiguous genitalia in girls. Parents may choose to delay surgery until the child is old enough to help make the decision.

Nonclassic CAH

Unlike classic CAH, the nonclassic form is mild and not life threatening. Signs and symptoms might not appear until childhood or adulthood.

Signs and symptoms

Signs and symptoms in both males and females include:

  • Early development of armpit and pubic hair
  • Early or severe acne
  • Infertility or decreased fertility

Adolescent girls and adult women also may have:

  • Masculine characteristics such as facial hair and a deep voice
  • Infrequent or absent menstrual periods


Some patients have no symptoms and require no treatment. Others need low-dose glucocorticoids (which might help with fertility), but might not need life-long treatment.

What Does the Future Hold for People With CAH?

With proper care, people with either type of CAH can live long and healthy lives. In the meantime. researchers continue to explore better ways to diagnose and treat this condition.

Questions to ask your doctor

  • What kind of CAH does my child (or do I) have?
  • What are the options for treatment for my child (or for me)?
  • What are the risks and benefits of each of the treatment options?
  • Will my child need surgery? If yes, when?
  • Should I see a pediatric endocrinologist (or an endocrinologist)?