What is Classic CAH?

CAH is a genetic disorder where the adrenal glands cannot make cortisol properly due to an enzyme deficiency (most commonly 21-hydroxylase). The glands become enlarged ("hyperplasia") as they try harder to make cortisol.

What happens?

• Low Cortisol: Leads to Adrenal Insufficiency.
• High Androgens ("Male" Hormones): The gland shunts precursors into making testosterone instead.
• Low Aldosterone (sometimes): "Salt-Wasting" form, causing dangerously low sodium.

Signs in Infants:

• Girls: Ambiguous genitalia (enlarged clitoris) at birth due to high androgens in the womb.
• Boys: May look normal at birth, but can present with life-threatening salt-wasting crisis (vomiting, dehydration, shock) in the first few weeks.

Signs in Older Children:

• Rapid growth but early puberty (bone age advances quickly, leading to short adult height).
• Excess body hair, acne, deepening voice.

Treatment:

• Hydrocortisone: Replaces missing cortisol.
• Fludrocortisone: Replaces aldosterone (for salt-wasting type).
• Salt Supplementation in infancy.

Early diagnosis (through newborn screening) and treatment are critical for normal development.