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Health condition · Clinically reviewed

Congenital adrenal hyperplasia, from newborn screening to lifelong hormone care.

A group of inherited adrenal disorders. Now on the NHS newborn blood spot, and reshaped by new therapies like crinecerfont.

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Why trust this guide

  • 01

    Clinically reviewed

    Written by our editorial team and reviewed by a UK paediatric or adult endocrinologist before publication.

  • 02

    Sourced from guidance

    Checked against Endocrine Society, ESPE, NHS Newborn Blood Spot programme and peer-reviewed sources you can see at the end.

  • 03

    Current for 2026

    Reflects the addition of 21-hydroxylase CAH to the NHS UK newborn blood spot programme in 2025 and the arrival of crinecerfont.

Key facts

CAH at a glance.

The essentials, in plain English. What CAH is, the main forms, and how it is picked up and treated in the UK today.

  • What it is

    A group of autosomal recessive disorders of adrenal steroidogenesis. Around 95% of cases are caused by 21-hydroxylase deficiency due to CYP21A2 gene mutations.

  • Classic forms

    Salt-wasting (around 75% of classic) is a neonatal adrenal crisis risk. Simple virilising causes androgen excess with preserved mineralocorticoid function.

  • Non-classic form

    A milder late-onset form presenting in adolescence or adulthood with hirsutism, acne, oligomenorrhoea, infertility and PCOS-like features.

  • UK newborn screening

    21-hydroxylase CAH was added to the NHS UK Newborn Blood Spot programme in 2025, allowing early detection before crisis.

  • Foundation therapy

    Hydrocortisone replacement, with fludrocortisone in salt-wasting disease. Sick-day rules and an emergency injection kit are non-negotiable.

  • New options

    Crinecerfont (a CRF1 antagonist) was approved by the FDA in 2024 for classic CAH and is being reviewed by NICE.

Why this guide matters

A lifelong condition, with a clear plan.

CAH care in the UK has changed markedly in the past two years. The three points below shape the rest of the page.

  • Newborn screening changes everything

    21-hydroxylase CAH joined the NHS UK Newborn Blood Spot programme in 2025, allowing detection before a salt-wasting crisis in the second week of life.

  • Sick-day rules save lives

    Every family and adult with CAH needs a steroid emergency card, an IM hydrocortisone kit and training. Adrenal crisis is preventable but still fatal when missed.

  • New therapies are reshaping care

    Crinecerfont was approved by the FDA in 2024 and is being reviewed by NICE. Modified-release hydrocortisone (Efmody) and paediatric granules (Alkindi) already help match physiology.

How the diagnosis is made

From heel-prick to a specialist plan.

The steps a UK newborn screening team, paediatrician or endocrinologist will normally follow, in order.

  1. 01

    Detecting

    Newborn blood spot

    17-hydroxyprogesterone on the day-5 heel-prick card is now the primary UK screening test for 21-hydroxylase CAH.

  2. 02

    Detecting

    Clinical presentation

    Neonatal salt-wasting, atypical genitalia in a female baby, precocious puberty in a boy, or later hirsutism and menstrual disturbance.

  3. 03

    Detecting

    Baseline 17-OHP and androgens

    A high 17-hydroxyprogesterone (>200 nmol/L in classic disease, intermediate in non-classic) with raised androstenedione and testosterone.

  4. 04

    Confirming

    Short synacthen test

    The 17-OHP response to synthetic ACTH confirms non-classic CAH when the baseline is equivocal.

  5. 05

    Confirming

    Electrolytes and adrenal axis

    Sodium, potassium, glucose, cortisol, ACTH, aldosterone and renin identify salt-wasting and quantify glucocorticoid and mineralocorticoid deficiency.

  6. 06

    Planning

    CYP21A2 genetic testing

    A dedicated panel (mindful of the CYP21A1P pseudogene) confirms the diagnosis and supports cascade and prenatal counselling.

  7. 07

    Planning

    Specialist MDT

    Care is led by a specialist UK CAH centre such as Great Ormond Street, Alder Hey, Birmingham Children’s, Bristol, Royal Manchester or Sheffield.

Typical timeline: newborn screening result within the first two weeks, specialist plan within days of confirmation.

Symptoms

What CAH actually looks like.

Presentations differ by age and by form. Severe classic disease presents in newborns. Non-classic CAH often appears in adolescents and adults.

  • Neonatal salt-wasting crisis

    Vomiting, poor feeding, weight loss, hyponatraemia, hyperkalaemia and hypoglycaemia at around day 5 to 14. Life-threatening without urgent treatment.

  • Atypical genitalia in girls

    Clitoromegaly and labial fusion in a female baby from prenatal androgen exposure. See our guide to atypical genitalia.

  • Precocious puberty in boys

    Simple virilising CAH causes early pubic hair, accelerated growth and advanced bone age in boys with normal-appearing genitalia at birth.

  • Tall child, short adult

    Untreated androgen excess accelerates growth then fuses the growth plates early, so final adult height is reduced.

  • Hirsutism and acne

    Adult-onset facial and body hair with acne in non-classic CAH, often mistaken for polycystic ovary syndrome.

  • Menstrual irregularity

    Oligomenorrhoea, anovulation and reduced fertility in women with non-classic disease.

  • Subfertility

    Both classic and non-classic CAH can affect fertility in women and men. Specialist reproductive input helps.

  • Red flag – adrenal crisis

    Any child or adult with CAH who is unwell, vomiting, drowsy or hypotensive needs intramuscular hydrocortisone and emergency care.

Treatment

How CAH is treated in the UK.

Cortisol replacement is the backbone. Fludrocortisone, salt supplements, sick-day rules and, increasingly, crinecerfont are added as needed.

  • Emergency hydrocortisone

    Intravenous hydrocortisone with fluids, glucose and electrolyte correction for adrenal crisis. Every family needs an IM emergency kit at home.

  • Glucocorticoid replacement

    Thrice-daily oral hydrocortisone, Alkindi granules for infants and children, or Efmody modified-release capsules for adults. Doses are individualised.

  • Fludrocortisone

    Mineralocorticoid replacement for salt-wasting CAH, titrated against blood pressure, sodium, potassium and renin.

  • Sodium chloride supplements

    Added salt for infants with salt-wasting disease until weaning is established.

  • Sick-day rules and steroid card

    Double or triple oral dose for illness, IM hydrocortisone for vomiting, an NHS steroid emergency card and family training. Non-negotiable.

  • DSD and reconstructive care

    A specialist disorders of sex development service supporting families of girls with atypical genitalia, with any surgery delayed, reversible and patient-centred.

  • Crinecerfont (Crenessity)

    A CRF1 antagonist that reduces ACTH and androgens and lowers the glucocorticoid dose needed. FDA approved in 2024, NICE review pending in the UK.

  • Non-classic hormonal therapy

    Low-dose hydrocortisone, the combined oral contraceptive and antiandrogens such as spironolactone for hirsutism, acne and fertility support.

What this guide is based on

The sources behind every claim on this page.

International specialist guidance and UK screening and prescribing standards, current at the time of last review.

Key references

Guidelines and standards we relied on.

A quiet reminder

This guide is for information, not medical advice.

Your endocrine team knows your history and can tell you which parts apply to you. If in doubt, contact them or seek urgent care.

  • Endocrine Society. Congenital adrenal hyperplasia due to steroid 21-hydroxylase deficiency: clinical practice guideline.

  • European Society for Paediatric Endocrinology (ESPE). Consensus statements on CAH and DSD.

  • NHS Newborn Blood Spot Screening Programme. 21-hydroxylase CAH condition information, 2025.

  • MHRA and NHS England. Steroid emergency card and sick-day rules for adrenal insufficiency.

  • FDA. Crinecerfont (Crenessity) approval for classic congenital adrenal hyperplasia, 2024.

Red flags

When CAH needs urgent attention.

Most CAH is stable on a good plan. These are the situations that are not, and where specialist input is essential.

  • Adrenal crisis

    Vomiting, drowsiness, hypotension or collapse in a child or adult with CAH is an emergency. Give IM hydrocortisone and call 999.

  • Missed newborn presentation

    A previously well baby who becomes floppy, dehydrated or hypoglycaemic in the second week of life needs urgent electrolytes and a paediatric review.

  • Illness or surgery without stress cover

    Any significant illness, fever, injury, general anaesthetic or procedure needs planned steroid stress dosing.

  • Precocious puberty in a young child

    Early pubic hair, rapid growth or advanced bone age needs paediatric endocrine assessment for CAH and other causes.

  • Atypical genitalia in a newborn

    A sensitive, urgent MDT assessment in a specialist DSD centre, avoiding sex assignment until investigations are complete.

  • New hirsutism with menstrual change

    Adult hirsutism, acne and oligomenorrhoea deserve a 17-OHP check to look for non-classic CAH, not just a PCOS label.

  • Pregnancy in a woman with CAH

    Needs joint endocrine and obstetric care, glucocorticoid adjustment and genetic counselling for the baby.

  • Poor growth or excessive weight gain

    Suggests over-treatment or under-treatment with hydrocortisone. Prompts a specialist dose review.

  • Transition to adult services

    The teenage years are a high-risk period for missed doses and crisis. A planned paediatric-to-adult handover matters.

Living with it

A lifelong condition, managed by people who know it.

Four things that make the biggest difference day to day. The card, the kit, the timing and the community around you.

A quiet reminder

Sick-day rules save lives.

If you or your child cannot keep tablets down, give the IM hydrocortisone injection and get emergency help. Do not wait to see if it settles.

  1. 01 Emergency

    Carry the card and the kit

    A steroid emergency card, an IM hydrocortisone injection kit and a family trained to use it. This is what prevents a fatal crisis.

  2. 02 Routine

    Take doses on time

    Thrice-daily hydrocortisone works best when taken at the same times each day. Modified-release capsules suit some adults.

  3. 03 Illness

    Double or triple for sick days

    Fever, vomiting, diarrhoea or injury means double or triple the oral dose, and IM hydrocortisone if you cannot keep tablets down.

  4. 04 Support

    You are not on your own

    CAH Support Group UK, Living with CAH and specialist nurses at your paediatric or adult endocrine centre offer real, ongoing help.

Frequently asked

Everything we get asked about CAH.

Quick answers on classic and non-classic forms, newborn screening, treatment and new therapies.

  • What is congenital adrenal hyperplasia?

    Congenital adrenal hyperplasia is a group of inherited conditions in which the adrenal glands cannot make cortisol normally. Around 95% of cases are caused by 21-hydroxylase deficiency due to mutations in the CYP21A2 gene. The block in cortisol production drives ACTH up, the adrenals enlarge, and androgen production increases as a byproduct.

  • What are the different forms?

    There are two classic forms. Salt-wasting CAH (around 75% of classic cases) causes a life-threatening neonatal crisis with cortisol and aldosterone deficiency. Simple virilising CAH causes androgen excess but preserved salt handling, with atypical genitalia in girls and precocious puberty in boys. Non-classic CAH is a milder, late-onset form presenting in adolescence or adulthood with hirsutism, acne, irregular periods and reduced fertility.

  • How is CAH picked up in newborn babies?

    21-hydroxylase CAH was added to the NHS UK Newborn Blood Spot programme in 2025. The day-5 heel-prick card measures 17-hydroxyprogesterone, and raised levels prompt urgent confirmatory tests. Early detection allows treatment to start before a salt-wasting crisis in the second week of life.

  • How is CAH treated?

    The mainstay is glucocorticoid replacement with hydrocortisone, using Alkindi granules for infants and children or Efmody modified-release capsules for adults. Salt-wasting disease also needs fludrocortisone and, in infancy, added sodium chloride. Sick-day rules, a steroid emergency card and an IM hydrocortisone kit are essential for every patient.

  • What is crinecerfont?

    Crinecerfont (Crenessity) is a CRF1 receptor antagonist that reduces ACTH drive to the adrenal glands, lowering androgens and allowing the glucocorticoid dose to come down. It was approved by the FDA in 2024 for classic CAH and is being reviewed by NICE for use in the UK.

  • Can adults have CAH without knowing?

    Yes. Non-classic CAH often looks like polycystic ovary syndrome, with hirsutism, acne, irregular periods and subfertility. A 17-hydroxyprogesterone level, with a short synacthen test if needed, will pick it up. Diagnosis matters because treatment, family screening and fertility care all change.

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