Type 1 Diabetes

Type 1 diabetes is an autoimmune condition in which the immune system mistakenly attacks and destroys the insulin-producing cells in the pancreas. Without insulin, the body can't move glucose from the blood into cells, so blood sugar rises to dangerous levels.

How It Differs From Type 2

Unlike type 2 diabetes, type 1 isn't caused by insulin resistance, weight, or lifestyle factors, and it can't be prevented or reversed with diet and exercise. It's most often diagnosed in children, teenagers, or young adults, though it can occur at any age. Because the pancreas stops producing insulin entirely, treatment always requires insulin — through injections or an insulin pump — for life.

Symptoms

Type 1 diabetes symptoms often appear suddenly, over days to weeks: increased thirst, frequent urination, unexplained weight loss, fatigue, and blurred vision. In some cases, it's first diagnosed when a person develops diabetic ketoacidosis (DKA), a serious complication requiring emergency treatment.

Diagnosis

Type 1 diabetes is diagnosed with the same blood glucose or HbA1c tests used for diabetes generally. To confirm type 1 specifically — rather than type 2 or another form — a doctor may also test for islet autoantibodies (antibodies that mistakenly target the insulin-producing cells) and check a C-peptide level, which reflects how much insulin the pancreas is still making.

Living With Type 1 Diabetes

Day-to-day management involves regularly monitoring blood sugar, calculating and administering insulin doses around meals and activity, and adjusting for factors like illness or exercise. Because insulin therapy lowers blood sugar, it also carries a risk of blood sugar dropping too low (hypoglycemia), so learning to recognize and treat low blood sugar quickly is a core part of daily management. With proper management, people with type 1 diabetes can live long, full lives — though it requires ongoing attention that type 2 diabetes managed by lifestyle alone doesn't.