Congenital Hyperinsulinism: Causes, Symptoms, and Treatment
Medically reviewed by Achuta Uppu, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Congenital Hyperinsulinism?
A pediatric endocrinologist, a doctor who treats hormone problems in children, is part of the care team. Care often happens at a center with specialists such as endocrinologists and surgeons who know this condition well. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is congenital hyperinsulinism?
Congenital hyperinsulinism is a rare condition that babies are born with. The pancreas makes too much insulin. Insulin is a hormone that moves sugar from the blood into cells. When there is too much insulin, blood sugar, also called blood glucose, drops too low. Doctors call this low blood sugar hypoglycemia.
The brain runs on blood sugar for fuel. So low blood sugar can cause serious problems when it is not treated. Low blood sugar can happen when a child has not eaten. In this condition it can also happen after a meal.
Symptoms
Symptoms come from low blood sugar. In babies and young children they include:
- Low energy and sleepiness.
- Irritability and crankiness.
- Trouble feeding and excessive hunger.
- Rapid heartbeat.
Older children and adults may feel shaky, weak, tired, or confused. Very low blood sugar can cause seizures or coma. Repeated low blood sugar episodes can also lead to breathing trouble, vision loss, brain damage, and learning problems.
Causes and who gets it
Congenital hyperinsulinism comes from changes in genes that control how the pancreas releases insulin. Insulin is made by beta cells, cells inside the pancreas. In this condition the beta cells release insulin even when blood sugar is already low. Changes in at least nine genes can cause it. The most common is a gene called ABCC8.
The condition can run in families. In the diffuse form, all of the beta cells make too much insulin. This form is usually inherited when a child gets a changed gene from both parents. Less often, one changed gene is enough. In the focal form, only some beta cells are affected.
About 1 in 50,000 newborns have this condition.
How doctors diagnose it
Doctors check blood sugar during a low episode. They also check insulin levels in the blood during the episode. They look for signs of too much insulin action, such as low levels of ketones, substances the body usually makes when blood sugar drops. A rise in blood sugar after a shot of glucagon, a hormone that raises blood sugar, also points to too much insulin. Some babies need a fasting test in the hospital to confirm it.
Genetic testing finds the gene change. It is also the most useful test for telling how likely it is that the disease is focal, which means it sits in one small area. To find where that area is, doctors use a special scan called an 18F-DOPA PET scan. It uses a small amount of a radioactive drug and is the most effective way to find a focal lesion, the small patch of abnormal beta cells.
Treatment
Fast treatment is essential because the brain has no other fuel when blood sugar is low. A sugary drink helps a mild episode. For severe low blood sugar, glucose goes into a vein, or glucagon is injected.
Medicines used to treat this condition include diazoxide, octreotide, and glucagon. Diazoxide works for some forms of the condition but often not for the KATP form, a form caused by broken channels on beta cells. Diazoxide can cause fluid retention, a particular problem for newborns, and octreotide can cause gallstones.
Surgery helps some children. In the focal form, removing only the affected part of the pancreas can cure the condition. In the diffuse form, surgery is not a cure. Children may still need frequent feeds and medicine after surgery.
When to see a doctor
Babies with trouble feeding, low energy, or shakiness need prompt checking by a doctor. Call 911 or your local emergency number right away for a seizure, passing out, a baby who is very sleepy or hard to wake, trouble breathing, or blue or gray skin.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. For this rare condition, such a doctor can help coordinate care and refer you to specialists such as an endocrinologist.
Common questions
Is congenital hyperinsulinism the same as hyperinsulinemia?
No. In congenital hyperinsulinism, gene changes make beta cells release insulin all the time, and blood sugar drops. Hyperinsulinemia is a different condition, though it also involves too much insulin.
Will a child outgrow it?
It depends on the form. Some babies have a short-term form that goes away after a few days to months. Genetic forms do not go away, but they may become easier to treat as the child gets older.
Can it cause brain damage?
Long or repeated low blood sugar episodes can damage the brain. They can lead to seizures, learning problems, or vision loss. With early treatment and close control of low blood sugar, brain damage can be prevented. But brain damage can still happen if the condition is not recognized or if treatment does not control the low blood sugar.
What is the difference between the diffuse and focal forms?
In the diffuse form, every beta cell in the pancreas makes too much insulin. In the focal form, only a small area of beta cells is affected. Surgery can cure the focal form, but not the diffuse form.
Sources
- MedlinePlus - Congenital hyperinsulinism
- National Organization for Rare Disorders - Congenital Hyperinsulinism
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
