Health Library
Congenital Adrenal Hyperplasia

What is CAH?

  • Congenital Adrenal Hyperplasia (CAH) is a condition of the adrenal glands that people are born with. The adrenal glands sit on top of the kidneys and make hormones. Hormones are chemical signals. The adrenal glands make three different types of hormones: cortisol, aldosterone, and androgens. Cortisol controls energy and blood sugar levels.
  • Aldosterone controls salt and water levels.
  • Androgens are a group of hormones, not a single hormone. They are male sex hormones. Androgens from the adrenal glands control body changes during puberty in both girls and boys. These changes include body hair in the armpits and genital area, body odor, and acne.
  • CAH results when the adrenal glands cannot make one or more of these hormones. Most commonly, the adrenal glands cannot make enough cortisol and aldosterone and make too much androgen.

    CAH can be masculinizing, feminizing, salt-wasting or non-salt-wasting.

    • Masculinizing: The adrenal glands in some girls with CAH make too much androgen. This makes their genitals look like a boy’s.
    • Feminizing: The adrenal glands in some boys with CAH make too little androgen. This makes their genitals look more like a girl’s.
    • Non-Classic (Late-Onset): The adrenal glands in some children with CAH start making too much androgen later in childhood. Boys and girls with this form have typical genitals at birth. They can have puberty changes early. This form is also called late-onset.
    • Salt-Wasting: The adrenal glands in some people with CAH make too little aldosterone. This causes salt to be lost in the urine and requires medication to be taken.
    • Non-Salt Wasting: The adrenal glands in some people with CAH make enough aldosterone. Usually people with non-salt-wasting CAH have milder symptoms.

    Masculinizing and feminizing CAH are also called differences in sex development (DSD). DSD are a group of conditions in which the genitals or reproductive parts do not develop in a typical way before birth.

    What Causes CAH?

    People with CAH i are born with a missing enzyme that is not working properly. Enzymes are proteins that cause chemical changes. The adrenal glands need enzymes to make hormones from their building blocks. The most common type of CAH, the enzyme “21-hydroxylase” is missing or not working. Here, we are talking mainly about the most common type of CAH.

    • If the enzyme is missing or not working at all, the adrenal gland cannot make cortisol or aldosterone from their building blocks.
    • If the enzyme is only partially working, the adrenal gland makes less cortisol than the body needs. The adrenal gland may still make enough aldosterone to prevent salt-wasting.
    • If the enzyme cannot change the building block into cortisol and aldosterone, they get changed into more androgen instead.

    When Is CAH Suspected?

    Physical Exam

    Baby boys with CAH usually look typical at birth. The extra androgens do not usually change the way their genitals look.

    Baby girls with CAH may have changes in the way their genitals look. The clitoris may be enlarged. The clitoris is a sensitive part of a woman’s body involved in sexual arousal. Their labia may be fused. The labia are folds of skin. This may make the labia look like a scrotum.

    CAH does not affect the reproductive parts inside boys’ and girls' bodies.

    Children with non-classic CAH may not show any signs until they are older.

    In children and adults with CAH, the extra male hormones may cause the following symptoms:

    • Rapid growth
    • Advanced bone age (their bones mature too fast)
    • Short height as adults
    • Early acne and body hair in boys and girls
    • Excess body hair and / or acne in girls or women
    • Difficulties with periods or getting pregnant in girls or women

    Adrenal Crisis

    Some people have a more severe form of CAH. This happens when the enzyme is missing or not working at all. People with this form of CAH are at a risk for an “adrenal crisis.” An adrenal crisis is the result of a very low cortisol and aldosterone levels. This can occur at any age. It is very serious, and can be life threatening.

    Signs of adrenal crisis include:

    • Poor feeding or appetite
    • Vomiting
    • Diarrhea
    • Sleepiness
    • Weak cry in infants
    • Dehydration
    • Low blood pressure
    • Weight loss

    How Is CAH Diagnosed?

    The doctors may do tests, such as:

    • Newborn Screen: This is a blood test that looks for many different conditions. All infants are tested in the first one to three days of life, even if they are not sick.
    • Karyotype: This is a blood test that looks for changes in genes that cause CAH.
    • Genetic testing: This is a blood test that looks for changes in genes that cause CAH.
    • Hormone testing: These are blood tests that check what hormones the adrenal gland is making and how much.
    • Pelvic ultrasound: This is an imaging test that looks for the gonads and for a uterus. The gonads are glands that make hormones, eggs and sperm.
    • Laparoscopy: This is a surgery using a small camera. The surgeon looks for the reproductive parts inside the body.

    How Do We Treat People with CAH?

    Treatment for people with CAH is life-long. It requires daily hormone replacement (medications).

    • Oral hydrocortisone (Cortef) replaced cortisol.
    • Oral fludrocortisone (Florinef) replaces aldosterone. It treats salt-wasting CAH.

    Hormone replacement helps decrease androgen levels.

    Parents may ask for surgery to make their daughter’s genitals look and function more typically. Not having surgery is an option some choose. This surgery can be done in infancy. It can also be done later when the girl is old enough to make her own decisions. Families should take time to consider the options carefully. Our team talks with parents about all of the options and helps them make decisions.

    Care By the Team

    All children with CAH have routine office visits with an endocrinologist. An endocrinologist is a doctor who treats patients with hormone conditions. She / he checks patients’ growth and hormone levels. Endocrinologists also prescribe the medicine that treats CAH.

    If a girl is born with genitals that appear more male, she may also see other doctors. These doctors may include gynecologists and urologists. Gynecologists care for girls’ reproductive parts inside and outside their bodies.

    The reproductive parts outside the body are called “genitals.” Urologists treat boys’ and girls’ genitals and urinary tracts. The urinary tracts are the body parts that make urine.

    Our DSD team is made up of different types of doctors. Our DSD team also includes psychologists, geneticists, genetic counselors, child life specialists, social workers and ethicists. We provide care at all of the stages of growing up, and treatment depends on each patient’s individual needs. Our team helps patients and families understand treatment options, answers questions, and addresses concerns. Concerns can be related to emotions, behaviors, development or adjustment. Our team also provides support and counseling. We want all our patients and families to experience the best quality of life possible.

    Illness and Emergencies

    "Stress dose" during illnesses

    • Illness or injury affects your body. Cortisol helps the body recover from serious illness or injury, so medication needs to be given. The following are examples of serious illnesses or injuries.
      • Fever > 100 degrees F
      • Severe throat, ears, lungs, or urinary tract infections
      • Broken bones and other traumatic injuries
      • Vomiting or diarrhea

    People with CAH need higher doses of cortisol to heal from serious illnesses or injuries. This extra cortisol is known as the “stress dose.” It is usually given by mouth. When a person with CAH has vomiting or diarrhea, the stress dose needs to be given as an injection (shot) into the muscle. The stress dose may need to be given for several days. We teach families when and how to give stress doses for illness.

    When to call the doctor

  • Fever >100 degrees F, severe infections, broken bones or other traumatic injuries, vomiting or diarrhea.
  • If you have questions about whether or not to give your child a stress dose of cortisol.
  • If you have questions about how much cortisol to give. If you have questions about whether or how to give the cortisol as a shot.
  • If your child’s illness or condition has not improved after getting several stress doses of cortisol.
  • Emergencies

    Shots of stress dose cortisol are given in emergencies. If your child looks sick and is pale, sweaty, breathing fast, unable to respond, unconscious, or has a serious injury, this is an EMERGENCY. Your child could die if he / she does not receive a stress dose cortisol shot immediately. In an emergency, you should:


    To be prepared for an emergency:

    • You should always carry a shot of cortisol with your child. This is just in case.
    • Your child should wear personal identification that says he / she has CAH. One type of personal identification is Medic-Alert bracelet.
    • All of your child’s caregivers should save his / her doctor’s phone number in their cell phones.

    What To Expect

    With appropriate treatment, children with CAH grow up healthy and are able to do everything children without CAH can do. They participate fully in school activities, sports and social events. Girls and women with CAH can have regular periods and can have children. Treatment is life-long, and adolescents and adults need to continue to see their endocrinologist and / or medical team and take their medicine. With good care, people with CAH are healthy and do well.

    Last Updated 09/2021

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