Type 1 diabetes is an autoimmune condition in which the body makes little or no insulin. Because insulin is needed to move glucose from the blood into cells, people with type 1 diabetes need insulin treatment.
Quick summary
Type 1 diabetes is not caused by eating too much sugar. It can happen at any age, and symptoms can become serious quickly if insulin is missing.
Key takeaways
- Type 1 diabetes requires insulin.
- Symptoms can include thirst, frequent urination, weight loss, tiredness, blurry vision, nausea, or vomiting.
- Diagnosis uses blood tests, and antibody testing may be used in selected cases when the diabetes type is unclear.
- Sick-day and ketone plans are important safety tools.
Why early recognition matters
When the body does not have enough insulin, glucose rises and the body may begin making ketones. High ketones can lead to diabetic ketoacidosis, a medical emergency.
Care often includes insulin, glucose monitoring, carbohydrate awareness, physical activity planning, supplies, education, and support for school, work, travel, and illness.
What daily care may include
- Basal insulin and mealtime insulin, or insulin pump therapy.
- Fingerstick glucose checks or continuous glucose monitoring.
- A plan for low blood sugar.
- A plan for illness, ketones, and vomiting.
- Regular review of doses, devices, meals, and activity.
Practical takeaway
Type 1 diabetes care is daily work. The goal is safer patterns and fewer emergencies, not perfect numbers every day.
Safety note
This article is not a substitute for medical care. Seek urgent care for vomiting, moderate or large ketones, severe low blood sugar, confusion, trouble breathing, dehydration, or symptoms of diabetic ketoacidosis.
What to ask your care team
- Which numbers, symptoms, or medicines matter most for my situation?
- What changes should I make only with medical advice?
- When should I seek urgent help instead of waiting for a routine appointment?
Related reading
Source summary
- About Type 1 Diabetes, Centers for Disease Control and Prevention. Patient guidance. Accessed June 5, 2026. Source
- Diabetes Symptoms, Centers for Disease Control and Prevention. Patient guidance. Accessed June 5, 2026. Source
- Diabetes Testing, Centers for Disease Control and Prevention. Patient guidance. Accessed June 5, 2026. Source
- Insulin, Medicines, and Other Diabetes Treatments, National Institute of Diabetes and Digestive and Kidney Diseases. Patient guidance. Accessed June 5, 2026. Source