What Is Congenital Adrenal Hyperplasia (CAH)? Symptoms, Causes, Diagnosis & Treatment Explained
Updated: 3 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
Quick Answer: What is congenital adrenal hyperplasia?
Congenital adrenal hyperplasia (CAH) is an inherited genetic condition in which the adrenal glands can't make enough cortisol and aldosterone while overproducing androgens [2]. Classic CAH is found at birth and requires daily medication for life [2] [4], while nonclassic CAH is milder and may need little or no treatment [2] [4]. With early detection and consistent medication, most people with CAH have good health [2].
Key takeaways
What it is: a group of genetic disorders affecting the adrenal glands and their hormone production [1].
Hormones involved: cortisol (stress response, blood pressure, energy, blood sugar), aldosterone (salt, water, blood volume), and androgens (puberty, growth).
Underlying problem: a missing enzyme causes too little cortisol, too little aldosterone, and too much androgen [2].
Two main types: classic CAH and nonclassic CAH; 21-hydroxylase deficiency causes about 95% of all cases [4].
Classic CAH: more serious; diagnosed at birth [2]; can cause shock and coma if untreated; two subtypes.
Nonclassic CAH: the mildest form; may appear later in childhood, adolescence or adulthood; may cause no symptoms [2] [5].
How common (classic): as many as 1 in 10,000-15,000 people in the U.S. and Europe [4].
How common (nonclassic): about 1 in 100-200 people [4].
Main cause: a genetic mutation causing a shortage or absence of the enzyme 21-hydroxylase (most common) or 11-hydroxylase (less common) [4].
Inheritance: autosomal recessive — a mutated gene copy from both parents [3] [4].
Newborn screening: a heel-prick blood test before leaving the hospital detects classic CAH [2].
Classic CAH treatment: salt supplements, glucocorticoids and mineralocorticoids, taken daily for life [2] [4].
Nonclassic CAH treatment: often no treatment; mild cases may need low-dose glucocorticoids [4] [5].
Prognosis: good with early detection and medication; most people lead healthy, productive lives [2] [5].
What the research says
Classic CAH occurs in roughly 1 in 9,500 births worldwide, with large differences between countries. In a systematic review and meta-analysis of 58 studies from 31 countries (1969-2017), the overall incidence of classic CAH (salt-wasting and simple-virilizing forms) was 1 in 9,498 births (95% CI 1 in 9,089 to 1 in 9,945). The highest incidence was reported in Eastern Mediterranean and Southeast Asian countries, and incidence was lower among people identified as Black or of African descent than among Hispanic/Latino and White groups. Data from sub-Saharan Africa and parts of Europe were insufficient, and nonclassic CAH was not included (Navarro-Zambrana & Sheets, Horm Res Paediatr, 2023) [7].
Evidence on the best glucocorticoid dosing is still thin. A Cochrane review of glucocorticoid replacement regimens for 21-hydroxylase deficiency CAH found 5 randomized trials with 101 participants in total (ages 3.6 months to 21 years; 2 weeks to 6 months per treatment arm). The trials were too different to pool, the evidence was very low quality, and none reported quality of life, prevention of adrenal crisis or final adult height, so the review could not say which regimen is best (Ng et al., Cochrane Database Syst Rev, 2020) [8].
What Is Congenital Adrenal Hyperplasia?
Congenital adrenal hyperplasia (CAH) is a group of genetic disorders affecting your adrenal glands [1]. You have one adrenal gland on top of each kidney. The adrenal glands produce important hormones your body needs to function properly.
If you have CAH, your adrenal glands lack an enzyme they need to make vital hormones for your body [1]. These glands normally produce three key hormones, each with a distinct job:
Hormone | What it does |
Cortisol | Helps your body respond to illness, injury and stress; regulates blood pressure, energy levels and blood sugar levels |
Aldosterone | Maintains correct levels of salt (sodium) and water; controls blood pressure and blood volume |
Androgens | Male sex hormones such as testosterone; kick off puberty and play an important role in normal growth and development |
Without the missing enzyme, your adrenal glands may not produce enough cortisol, may not produce enough aldosterone, and may produce too much androgen [2].
What are the different types of CAH?
There are two main types of CAH: classic congenital adrenal hyperplasia and nonclassic congenital adrenal hyperplasia. About 95% of all cases are caused by 21-hydroxylase deficiency [4].
#### Classic CAH
Classic CAH is the more serious form of the disease [2]. It can cause adrenal complications such as shock and coma. If not found and treated early, it can be fatal [5]. Diagnosis of classic CAH typically happens at birth [2]. There are two subtypes:
Subtype | Severity | What happens |
Salt-wasting CAH | Most severe form [2] | Adrenal glands produce too little aldosterone, so the body can't regulate salt (sodium) levels in the blood; too much sodium is lost through urine [2]. The body also produces too little cortisol and too much androgen. |
Simple-virilizing CAH (non-salt wasting) | More moderate form | Aldosterone deficiency is less severe. No life-threatening symptoms [2]. The body still doesn't produce enough cortisol and makes too much androgen; the androgen increase may cause symptoms related to sexual development. |
#### Nonclassic CAH
Nonclassic CAH is the mildest form of CAH. It usually doesn't show up until later in childhood, adolescence or adulthood [2] [5]. You may or may not see symptoms [5]. The overproduction of androgens may cause symptoms related to sexual development. There are several other rare forms of CAH [4], each with different symptoms.
Who does CAH affect?
Congenital adrenal hyperplasia can affect anyone. It affects infants, children and adults [1].
How common is congenital adrenal hyperplasia?
Both classic and nonclassic CAH affect people worldwide.
Symptoms of Congenital Adrenal Hyperplasia
CAH can cause various symptoms depending on the type and your sex.
Symptoms of classic CAH
Classic CAH causes high levels of androgens in your body. Elevated androgen levels may lead to symptoms related to your sex hormones. In both salt-wasting and non-salt wasting classic CAH, symptoms may include:
Symptom | Description |
Ambiguous genitalia in female infants | |
Enlarged penis in male infants [5] | Noticeable in newborn boys |
Premature signs of puberty | Voice changes, severe acne and early pubic, armpit and facial hair |
Male characteristics in females | Bulky muscles, a deep voice and excess facial hair |
Rapid growth | Faster-than-expected growth in childhood [2] |
Abnormal menstrual periods | Irregular or disrupted cycles |
Benign testicular tumors | Noncancerous tumors of the testicles |
Infertility | Difficulty conceiving |
In addition, the hormonal imbalances caused by salt-wasting CAH may result in severe adrenal symptoms:
Severe adrenal symptom | Description |
Dehydration | Excessive fluid loss [2] |
Low blood sodium (hyponatremia) | Salt levels drop dangerously low |
Low blood pressure (hypotension) | Blood pressure falls below normal [4] |
Irregular heartbeat (arrhythmia) | Abnormal heart rhythm [2] |
Low blood glucose | Blood sugar drops too low [2] |
Metabolic acidosis | Too much acid content in the blood |
Vomiting | Gastrointestinal distress [2] |
Diarrhea | Further fluid and salt loss [3] |
Weight loss | Ongoing loss of weight [2] |
Shock | Severe, life-threatening circulatory collapse [2] |
Symptoms of nonclassic CAH
Nonclassic CAH is a milder form of the disease. You may be unaware you have this form. Symptoms may include:
Symptom | Description |
Rapid growth | Faster-than-expected childhood growth [5] |
Acne | |
Precocious (early) puberty | Puberty arriving earlier than typical [2] |
Excess facial or body hair in females | |
Irregular menstrual periods | |
Infertility | |
Male-pattern baldness | Thinning hair in a typical male pattern |
Enlarged penis but normal testicles in males [2] | Distinctive physical finding |
What Causes Congenital Adrenal Hyperplasia?
The shortage or absence of an enzyme called 21-hydroxylase is the most common cause of CAH [4]. Genetic mutations affect your levels of this enzyme. Less commonly, the absence of an enzyme called 11-hydroxylase causes CAH [4].
CAH is an autosomal recessive disorder. You receive two copies of every gene in your body — one from each parent. CAH occurs when you inherit a mutated copy of the gene that causes the deficiency from both of your parents [3] [4].
How Is Congenital Adrenal Hyperplasia Diagnosed?
Diagnosis differs between the two main types, because classic CAH is caught at birth while nonclassic CAH is usually found only when symptoms appear.
Diagnosing classic CAH
Your baby's healthcare provider will screen them for CAH before they leave the hospital. This is part of the normal newborn screening. The provider does a blood test by pricking your newborn's heel. This screening determines whether your baby has classic CAH [2].
You may consider prenatal genetic testing if you're pregnant and already have one child with CAH. Your healthcare provider can check for CAH through amniocentesis or chorionic villus sampling [2].
Diagnosing nonclassic CAH
Diagnosis of nonclassic CAH may not occur until you or your child begin to show symptoms of the disease. In some cases, this may not happen until early adulthood [4]. A healthcare provider will diagnose nonclassic CAH through:
How Is Congenital Adrenal Hyperplasia Treated?
Treatment for CAH depends on the type and how severe your symptoms are. There isn't a cure for CAH, but you may find symptom relief with medications and other treatments [4].
Treating classic CAH
Your healthcare provider will monitor your condition. They'll order regular blood tests [2] to check your hormone levels. The goal of treatment is to ensure normal growth and sexual development [8].
Your provider may prescribe several medications to treat your symptoms:
Medication | What it replaces or provides |
Salt supplements (sodium chloride) | |
Glucocorticoids | |
Mineralocorticoids | Replace the aldosterone your body doesn't make on its own [2] |
If you have classic CAH, you'll need to take these medications daily for life [2] [4]. If you stop taking the medications, your symptoms will return.
Another treatment option is surgery for ambiguous genitalia. Surgery six to 12 months after birth can correct the appearance and function of your baby's genitals. [4] In some cases, it may be appropriate to delay surgery for several years.
Treating nonclassic CAH
If you don't have any symptoms, you may not need treatment. If you have mild symptoms, you may need a low dose of glucocorticoids [4] [5]. You usually won't need lifelong treatment [5].
If you or your child has CAH, it's important to seek mental healthcare to address any concerns. Mental healthcare is an important part of CAH treatment [1] and can lead to an improved quality of life.
Complications, Outlook and Prevention
What complications are associated with CAH?
Classic CAH causes you to lose too much water and salt in your urine [2]. You're at risk for serious complications, including imbalances of electrolytes like potassium. Left untreated, these imbalances can lead to:
Complication risk | Consequence if untreated |
Electrolyte (potassium) imbalances | Irregular heartbeat (arrhythmia) |
Irregular heartbeat | Cardiac arrest |
Cardiac arrest | Death |
Untreated nonclassic CAH can have complications as well:
Surgery to correct ambiguous genitalia carries its own risks of complications, including infection, bleeding and scarring.
What are the outcomes after treatment?
With early detection and medication, you can lead a healthy, productive life with CAH [5]. If you have classic CAH, you'll need to take your medications daily for life — if you stop, your symptoms will return.
Most people with CAH have good health, but you may be shorter than other adults [2]. In some cases, CAH can affect your fertility [2]. If you were born with ambiguous genitalia, you may need psychological care. Reach out to your healthcare provider if you need any help after treatment.
Can congenital adrenal hyperplasia be prevented?
You can't prevent CAH because it's a genetic condition [2]. If you have a family history of CAH or already have a child with CAH, you may want to consider genetic counseling and/or genetic testing [2]. You can learn about your risk of passing on the condition to your children.
How can I lose weight with CAH?
Certain medications used to treat CAH may cause weight gain. You should speak with your healthcare provider about your weight. They can help you determine if the weight gain is due to a medical issue. They may be able to adjust the dosages of your medication. They'll discuss with you a diet and exercise plan that can help you maintain a healthy weight.
Is CAH a disability?
Some agencies may consider adrenal disorders a disability. The complications caused by the specific disorder are looked at when determining if CAH qualifies as a disability.
Conclusion
Congenital adrenal hyperplasia is a genetic condition that changes the way the body's hormone factory works. Sitting on top of each kidney, the adrenal glands normally produce cortisol to handle stress, illness and injury; aldosterone to balance salt, water and blood pressure; and androgens to drive puberty and normal growth. In CAH, a genetic mutation removes a critical enzyme — most often 21-hydroxylase, and less often 11-hydroxylase [4] — and the whole balance shifts. The body falls short on cortisol and aldosterone while overproducing androgens [2].
The condition comes in two main forms, and about 95% of cases are caused by 21-hydroxylase deficiency [4]. Classic CAH, the serious form, is usually detected through the standard newborn heel-prick screening [2]. Its most severe subtype, salt-wasting CAH, drains salt and water from the body and can cause dehydration, dangerously low blood pressure, irregular heartbeat and even shock if untreated [2] [4] — which is why early detection is vital. Simple-virilizing classic CAH is less dangerous but still requires lifelong medication. Nonclassic CAH, by contrast, is mild enough that many people never know they have it; when it does surface, it typically does so in later childhood, adolescence or adulthood as rapid growth, acne, early puberty, excess facial hair or irregular periods [2].
CAH is inherited in an autosomal recessive pattern — a child must receive a mutated gene copy from both parents [3] [4]. Classic CAH affects as many as 1 in 10,000 to 15,000 people in the United States and Europe [4], while the nonclassic form is far more common, affecting about 1 in 100 to 200 people [4].
There is no cure, but treatment is effective [4]. People with classic CAH take salt supplements, glucocorticoids and mineralocorticoids every day for life, with extra doses during illness or stress [2] [4], and undergo regular blood tests to keep hormone levels on track [2]. Surgery to address ambiguous genitalia is an option in some cases. Most people with CAH live healthy, productive lives — though they may be shorter than average adults, may face fertility challenges [2], and may benefit from mental health support. Families with a history of CAH can pursue genetic counseling and testing to understand the risk of passing the condition on [2].
Because CAH touches hormones, growth, identity and family planning, support from endocrinology, mental health and genetics professionals — ideally beginning in infancy — makes a meaningful difference.
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Frequently Asked Questions (FAQ)
What is congenital adrenal hyperplasia?
Congenital adrenal hyperplasia (CAH) is a group of genetic disorders affecting your adrenal glands — the glands that produce hormones your body needs to function properly.
Where are the adrenal glands located?
You have one adrenal gland on top of each kidney.
What hormones do the adrenal glands produce?
The adrenal glands produce cortisol, aldosterone and androgens — hormones your body needs to function properly.
What does cortisol do?
Cortisol helps your body respond to illness, injury and stress, and regulates blood pressure, energy levels and blood sugar levels.
What does aldosterone do?
Aldosterone helps your body maintain correct levels of salt (sodium) and water, and controls blood pressure and blood volume.
What are androgens?
Androgens are male sex hormones such as testosterone. They kick off puberty and play an important role in normal growth and development.
What actually goes wrong in CAH?
If you have CAH, your adrenal glands lack an enzyme they need to make vital hormones, so they may not produce enough cortisol, may not produce enough aldosterone, and may produce too much androgen.
How many types of CAH are there?
Two main types — classic and nonclassic. About 95% of all cases are caused by 21-hydroxylase deficiency. Several other rare forms also exist, each with different symptoms.
What is classic congenital adrenal hyperplasia?
Classic CAH is the more serious form of the disease. It can cause adrenal complications such as shock and coma, and if not found and treated early, it can be fatal.
When is classic CAH diagnosed?
Diagnosis of classic CAH typically happens at birth, through newborn screening.
What is salt-wasting CAH?
Salt-wasting CAH is the most severe form. Adrenal glands produce too little aldosterone, so the body can't regulate salt levels in the blood, and too much sodium is lost through urine. The body also produces too little cortisol and too much androgen.
What is simple-virilizing CAH?
Simple-virilizing (non-salt wasting) CAH is a more moderate form. The aldosterone deficiency is less severe and there are no life-threatening symptoms, but the body still doesn't produce enough cortisol and makes too much androgen.
What is nonclassic congenital adrenal hyperplasia?
Nonclassic CAH is the mildest form. It usually doesn't show up until later in childhood, adolescence or adulthood, and you may or may not see symptoms.
Who can get CAH?
CAH can affect anyone — infants, children and adults.
How common is classic CAH?
Classic CAH affects as many as 1 in every 10,000 to 15,000 people living in the United States and Europe.
How common is nonclassic CAH?
Nonclassic CAH affects about 1 in every 100 to 200 people.
Does CAH occur worldwide?
Yes — both classic and nonclassic CAH affect people worldwide.
What causes CAH?
The shortage or absence of an enzyme called 21-hydroxylase is the most common cause. Less commonly, the absence of 11-hydroxylase causes CAH.
What is 21-hydroxylase?
An enzyme your adrenal glands need to make vital hormones. Genetic mutations affect your levels of it, and its shortage or absence is the most common cause of CAH.
How is CAH inherited?
CAH is an autosomal recessive disorder — it occurs when you inherit a mutated copy of the gene from both of your parents.
What does autosomal recessive mean?
You receive two copies of every gene, one from each parent. CAH occurs when both inherited copies of the gene that causes the deficiency are mutated.
What are the symptoms of classic CAH?
Symptoms include ambiguous genitalia in female infants, enlarged penis in male infants, premature signs of puberty, development of male characteristics in females, rapid growth, abnormal menstrual periods, benign testicular tumors and infertility.
What are the severe adrenal symptoms of salt-wasting CAH?
Dehydration, low blood sodium (hyponatremia), low blood pressure, irregular heartbeat, low blood glucose, metabolic acidosis, vomiting, diarrhea, weight loss and shock.
What is ambiguous genitalia in female infants?
The baby's external sex organs resemble typical male genitals, but the baby still has typical internal female organs.
Can CAH cause premature puberty?
Yes — premature signs of puberty may include voice changes, severe acne and early pubic, armpit and facial hair.
Can CAH cause male characteristics in females?
Yes — this may include bulky muscles, a deep voice and excess facial hair.
Can CAH cause infertility?
Yes — infertility is a recognized symptom of both classic and nonclassic CAH.
What are the symptoms of nonclassic CAH?
Symptoms may include rapid growth, acne, precocious (early) puberty, excess facial or body hair in females, irregular menstrual periods, infertility, male-pattern baldness, and enlarged penis with normal testicles in males.
Can you have nonclassic CAH without symptoms?
Yes — you may be unaware you have this milder form of the disease.
How is classic CAH screened in newborns?
Your baby's provider screens for CAH before they leave the hospital as part of normal newborn screening, with a blood test done by pricking the newborn's heel.
Can CAH be detected before birth?
If you're pregnant and already have one child with CAH, you may consider prenatal genetic testing through amniocentesis or chorionic villus sampling.
When is nonclassic CAH diagnosed?
Diagnosis may not occur until symptoms appear — in some cases not until early adulthood.
How is nonclassic CAH diagnosed?
Through physical examination, blood test, urine test and genetic testing.
Is there a cure for CAH?
No — there isn't a cure for CAH, but you may find symptom relief with medications and other treatments.
How is classic CAH treated?
With salt (sodium chloride) supplements, glucocorticoids to replace cortisol, and mineralocorticoids to replace aldosterone.
What are glucocorticoids for?
Glucocorticoids replace the cortisol your body doesn't make on its own. You may need extra during times of stress or illness.
What are mineralocorticoids for?
Mineralocorticoids replace the aldosterone your body doesn't make on its own.
Do people with classic CAH take medication for life?
Yes — if you have classic CAH, you'll need to take these medications daily for life. If you stop, your symptoms will return.
Can CAH surgery be performed?
Surgery for ambiguous genitalia is an option: six to 12 months after birth, surgery can correct the appearance and function of the baby's genitals. In some cases, it may be appropriate to delay for several years.
How is nonclassic CAH treated?
If you have no symptoms, you may not need treatment. With mild symptoms, a low dose of glucocorticoids may be needed — usually not lifelong.
Why is mental healthcare important in CAH?
Mental healthcare addresses concerns and is an important part of treatment, leading to an improved quality of life.
What complications can classic CAH cause?
Losing too much water and salt in urine risks electrolyte (like potassium) imbalances that, left untreated, can lead to arrhythmia, cardiac arrest and death.
What complications can untreated nonclassic CAH cause?
In males: early puberty and short stature. In females: permanent male body traits, irregular periods and infertility.
Does CAH surgery carry risks?
Yes — surgery to correct ambiguous genitalia carries risks of infection, bleeding and scarring.
What is the outlook for people with CAH?
With early detection and medication, you can lead a healthy, productive life. Most people with CAH have good health, though some may be shorter than other adults or have fertility challenges.
Can CAH affect height?
Yes — most people with CAH have good health, but you may be shorter than other adults.
Can CAH affect fertility?
Yes — in some cases, CAH can affect your fertility.
Do people born with ambiguous genitalia need psychological care?
They may need psychological care — and reaching out to your healthcare provider after treatment is encouraged.
Can CAH cause weight gain?
Certain medications used to treat CAH may cause weight gain. Your provider can determine if weight gain is due to a medical issue, adjust dosages, and discuss a diet and exercise plan.
Is CAH considered a disability?
Some agencies may consider adrenal disorders a disability, looking at the complications caused by the specific disorder when determining if CAH qualifies.
Can CAH be prevented?
No — you can't prevent CAH because it's a genetic condition.
Can genetic testing help with CAH?
If you have a family history of CAH or already have a child with CAH, genetic counseling and/or genetic testing can help you learn your risk of passing on the condition.
Related Reading
Precocious Puberty: Complete Guide to Signs, Causes, and Treatment
Female Infertility: Causes, Signs, and Treatment Options Explained
Male Infertility: Causes, Symptoms, Tests, and Treatments Explained
Dehydration: Symptoms, Causes, Risk Groups & Treatment — Complete Guide
Hyponatremia: Complete Guide to Low Blood Sodium, Symptoms, Causes, and Treatment
Hypoglycemia: Managing Low Blood Sugar Emergencies and Prevention
Heart Arrhythmia: Symptoms, Types, Causes, Diagnosis & Treatment — Complete Guide
Hirsutism: Causes, Symptoms, and the Treatment Options That Work
Testosterone Test: Types, Why It's Done, How to Prepare and What Results Mean explains how testosterone levels are measured and what a high result can mean.
DHEAS Test (DHEA Sulfate): Why It's Done and What Results Mean explains the adrenal hormone blood test used to check for PCOS and adrenal disorders.
References
Eunice Kennedy Shriver National Institute of Child Health and Human Development. Congenital Adrenal Hyperplasia (CAH). NICHD. Last reviewed May 17, 2021. Accessed October 15, 2026. https://www.nichd.nih.gov/health/topics/cah
National Library of Medicine. Congenital adrenal hyperplasia. MedlinePlus Medical Encyclopedia. Review date January 26, 2026; updated by Edens Hurst AC. https://medlineplus.gov/ency/article/000411.htm
Genetic and Rare Diseases Information Center. Congenital adrenal hyperplasia. GARD, NCATS/NIH. Last updated February 2026. https://rarediseases.info.nih.gov/diseases/1467/congenital-adrenal-hyperplasia
National Organization for Rare Disorders. Congenital Adrenal Hyperplasia. NORD Rare Disease Database. Last updated June 8, 2023; prepared with Speiser PW. https://rarediseases.org/rare-diseases/congenital-adrenal-hyperplasia/
National Adrenal Diseases Foundation. Congenital Adrenal Hyperplasia (CAH). NADF. Written by Speiser PW. Accessed October 15, 2026. https://www.nadf.us/congenital-adrenal-hyperplasia-cah.html
Speiser PW, Arlt W, Auchus RJ, et al. Congenital adrenal hyperplasia due to steroid 21-hydroxylase deficiency: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2018;103(11):4043-4088. PMID: 30272171. https://doi.org/10.1210/jc.2018-01865
Navarro-Zambrana AN, Sheets LR. Ethnic and national differences in congenital adrenal hyperplasia incidence: a systematic review and meta-analysis. Horm Res Paediatr. 2023;96(3):249-258. PMID: 35973409. https://doi.org/10.1159/000526401
Ng SM, Stepien KM, Krishan A. Glucocorticoid replacement regimens for treating congenital adrenal hyperplasia. Cochrane Database Syst Rev. 2020;3(3):CD012517. PMID: 32190901. https://doi.org/10.1002/14651858.CD012517.pub2
Medical disclaimer
This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider — such as an endocrinologist or pediatric specialist — with questions about a genetic or hormonal condition. Never stop or change prescribed medication without medical supervision, as untreated congenital adrenal hyperplasia can be life-threatening.
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