Congenital adrenal hyperplasia (CAH) is a genetic disorder caused by adrenal enzyme deficiency, which affects hormone production in the adrenal glands. CAH is a lifelong condition that has no cure, but it can be treated with medication. With proper treatment, most people who have CAH can lead a full life.
There are many types of CAH, but the most common is caused by the lack of an enzyme called 21-hydroxylase. This type of CAH is then broken down into two forms: classic and nonclassic, which depend on the severity of the condition.
Classic CAH
Classic CAH, a more serious and less common form of CAH, is often diagnosed at birth or in early infancy. Classic CAH is caused by a deficiency of 21-hydroxylase, which the body needs to make the hormones cortisol and aldosterone (which helps the body retain sodium). Without enough of these hormones, the adrenal glands start producing more of the male sex hormone androgens, including testosterone, which leads to hormonal imbalances.
There are two subtypes of classic CAH:
Salt-wasting CAH is the most common, more serious form of classic CAH. It occurs when the body makes too little aldosterone. This causes excessive sodium loss through urine, leading to dehydration and low blood pressure — and potentially life-threatening complications in untreated infants.
Simple-virilizing CAH is a less common and more mild form of classic CAH. It occurs when the body makes too much androgen and too little cortisol, which can disrupt typical sexual development in both boys and girls. Aldosterone is usually unaffected, though, so this form of CAH does not lead to significant sodium loss or related complications.
Nonclassic CAH
Nonclassic CAH is almost always caused by a partial (mild) deficiency of 21-hydroxylase, which doesn’t affect cortisol or aldosterone, but does lead to excess androgens. Symptoms usually appear before adulthood and include acne, early signs of puberty, and facial hair.
Signs and symptoms depend on CAH type. Sometimes, symptoms are more severe and appear within days after birth. Other times, the symptoms are so mild that CAH may not be diagnosed until later in life.
Classic CAH
The symptoms of both types of classic CAH are caused by higher levels of androgens, which results in sexual development issues, including:
Ambiguous genitalia (in girls)
Benign testicular adrenal rest tumors
Deep voice
Difficulty getting pregnant (in women) and infertility (in men)
Early facial hair (in boys)
Early signs of puberty
Enlarged penis
Excess body or facial hair (in girls)
Inability to menstruate or irregular menstrual cycles (in women)
Rapid growth in childhood and early teenage years, but still possibly shorter than both parents
Virilization (the development of male characteristics in a girl)
Salt-wasting CAH can come with more unique symptoms that appear in the days or weeks following birth, including:
Even after infancy, children with salt-wasting CAH can be at risk for adrenal crisis if they’re injured, sick, or under physical stress.
Nonclassic CAH
The symptoms of nonclassic CAH, caused by an increase in androgen production, usually appear in childhood, adolescence, or early adulthood. They typically affect sexual development. Some people have such mild symptoms that they never realize they have nonclassic CAH.
Male-pattern baldness (hair loss near the temples)
Rapid growth in childhood and early teenage years, but still possibly shorter than both parents
Small testicles
CAH is caused by a genetic mutation that results in a lack of 21-hydroxylase. This enzyme helps the adrenal glands — located in the upper abdomen — make essential hormones, such as aldosterone and cortisol. When the body is deficient in this enzyme, hormone production is disrupted, and androgen levels can become abnormally high.
Passed down in autosomal recessive patterns, CAH must be inherited by both parents. Usually, the parents are carriers, meaning they each carry one copy of the faulty gene but do not have CAH themselves. If both parents are carriers, there is a one in four chance their children will develop CAH.
If both parents have CAH, their children will definitely inherit the condition.
Testing for congenital adrenal hyperplasia can be done before or after birth, including into adulthood. If you and/or your partner have a family history of CAH and are expecting a baby, you can do one of the following prenatal tests to check for the condition:
Amniocentesis involves inserting a needle into the womb through the abdomen and withdrawing a small amount of fluid from the amniotic sac surrounding the fetus. The fluid is then tested to see if the fetus has a gene abornmality that causes CAH. The test is usually done between weeks 15 and 20 of pregnancy.
Chorionic villus sampling also involves inserting a needle into the womb, through the abdomen or cervix. A small piece of tissue is extracted from the chorionic villi, a membrane that will later form the placenta. The sample is then tested for the gene that causes CAH. The test is usually done between weeks 10 and 12 of pregnancy.
If CAH is detected in utero, you can work with a genetic counselor, maternal-fetal medicine specialist, and pediatric endocrinologist to get additional testing and come up with a plan to address your baby’s needs.
After birth, all infants are routinely screened for classic CAH with a heel stick test. (The test cannot detect nonclassic CAH.) If your child tests positive, they’ll undergo additional testing to confirm the diagnosis.
The symptoms of nonclassic CAH appear in adulthood, so if you suspect you or your child has the condition later in life, a doctor can make a diagnosis with some of the following tests:
Blood and urine tests (to measure hormone levels)
Genetic testing
Physical exam
X-ray (to measure the growth of bones during childhood)
The treatments for CAH include medication, psychological support, and surgery. The goal is to restore the body’s natural balance of hormones. Some people with CAH, including men with nonclassic CAH, may not need treatment.
CAH is usually treated by a doctor who specializes in hormonal issues, such as an endocrinologist (or pediatric endocrinologist in the case of children).
Medication Options
The doctor may prescribe medications for classic CAH to help balance out hormones. These include:
Mineralocorticoids (fludrocortisone) to replace aldosterone, which helps counter sodium loss, prevent adrenal crises, and boost growth and development in children
Glucocorticoids (dexamethasone, hydrocortisone, prednisolone, prednisone) to replace cortisol, which helps manage adrenal insufficiency, control androgens, and manage growth and development in childhood
Salt supplements (sodium chloride) to help retain salt in the body
People with CAH may need to take more glucocorticoids during stressful times, such as when sick, injured, or getting surgery. These are called “stress doses” and are given to reduce the risk of adrenal crisis. Occasionally, people with nonclassic CAH may also need stress doses, for childbirth, major surgery, or trauma.
One medication, crinecerfont (Crenessity), was approved by the U.S. Food and Drug Administration in 2024 to treat classic CAH in people 4 and older. The medication works by reducing pituitary stimulation to the adrenal glands, thereby lowering androgen levels in the body and reducing the required dose of glucocorticoids.
Some women with nonclassic CAH may also be given other treatments, including:
Corticosteroids, to help with fertility or decrease the risk of miscarriage
Oral contraceptives, to help regulate periods and treat acne and facial hair
spironolactone (Aldactone), to help treat acne and facial hair
Surgery
Parents of girls born with ambiguous genitalia may opt for surgery, especially if the genitals interfere with the ability to urinate. There’s not always a “best” time to have this procedure: Some parents schedule the surgery during the first 2 to 6 months of their child’s life. But many are encouraged to delay the decision about surgery and/or observation until the child is older and can be involved in the decision.
A multidisciplinary team, including a mental health provider, pediatric endocrinologist, and surgeon, can help you make the right decision for your child. Any surgery should be done at a center that specializes in genitoplasty.
CAH is a genetic condition. If you have a family history of CAH, you may want to work with a genetic counselor and have testing done to learn more about the risk of passing the condition on to your children. If the risk is very high, in vitro fertilization (IVF) with preimplantation genetic testing could be an option, to prevent having a child who has to live with severe disease.
When CAH is detected early, most people with the condition can lead a healthy life. People with classic CAH need to take medication every day — for life — to manage symptoms. People with nonclassic CAH may or may not need medication, depending on the severity of symptoms.
Some people who have CAH may be shorter than their peers. For some, the condition can also affect fertility, but most women with CAH should be able to conceive. Treatment, ongoing monitoring, and psychological support can help with managing the symptoms and allow for a full life.
If you have classic CAH, one of the most serious complications is adrenal crisis — an emergency resulting from dangerously low cortisol levels that needs to be treated right away. In infants, adrenal crises can occur within the first few days of life. But they can also happen in times of stress, such as during an illness or after an injury.
If nonclassic CAH requires treatment but is left untreated, it can cause complications such as early puberty and short stature. In women, it can lead to irregular menstrual cycles, infertility, and facial hair.
Classic CAH is estimated to affect 1 in 15,000 to 20,000 people at birth in Western countries. About 75 percent of the people who were diagnosed with the condition in infancy have salt-wasting CAH. The other 25 percent have simple virilizing CAH.
Nonclassic CAH affects about 1 in 1,000 people but can occur as frequently as 1 in 100 people in certain ethnic groups.
In the United States, classic CAH is more common among Native Americans and the Yupik people. Nonclassic CAH is most common among Ashkenazi Jews and Latinos.
Support groups and resources available to people with CAH and their caregivers include:
This organization is dedicated to advocating for and supporting people with CAH, as well as their parents and caregivers, via Zoom or telephone. They also have in-person meetings and Facebook groups.
The NADF informs and supports people with various adrenal diseases, including CAH, by offering education for patients, caregivers, and providers. The organization recently launched a podcast, “All Things Adrenal,” to spread awareness, education, and real stories from people living with CAH
This nonprofit organization aims to reduce the emotional and physical impact of growth-related endocrine disorders, including CAH, in people of all ages. It provides awareness about the importance of growth monitoring and connects people to expert resources and support groups.
Congenital adrenal hyperplasia (CAH) is a genetic disorder that causes an imbalance of certain hormones — primarily, too much androgen and too little cortisol.
There are two types of CAH: classic (which can cause adrenal crisis) and nonclassic (which can disrupt sexual development).
With the right treatment, most people with CAH can live a healthy life.
