Diabetes is a term for several conditions that involve how your body uses food to make energy. Most of the food you eat is converted to glucose, a type of sugar that provides energy to the cells. To enter the cells, glucose needs insulin, a hormone produced by the pancreas. Diabetes occurs when your body doesn’t produce insulin or is unable to use it effectively.

There are two main types of diabetes: Type 1 and Type 2. Although they share the same symptoms, the two types differ greatly in terms of cause, onset, and treatment. Because both types are chronic conditions that need daily management, it’s important to know which type you have and how to best address it.

Here are the key differences between Type 1 and Type 2 diabetes:

Causes

Type 1 diabetes is an autoimmune condition. It occurs when the immune system attacks the insulin-producing cells in the pancreas. When these cells are destroyed, the body no longer produces insulin at all.

The exact cause of type 1 diabetes is unknown. Suspected factors include genetics, exposure to certain viruses, and physical problems with the beta cells.

Type 2 diabetes occurs when your body doesn’t respond to insulin properly, a condition known as insulin resistance. Most patients still produce insulin, but they don’t make enough or their cells can’t use it effectively. This causes glucose to build up in the blood, causing high blood sugar.

Researchers aren’t sure what causes insulin resistance, but obesity and inactivity are common factors.

Onset

Type 1 diabetes, previously known as juvenile-onset diabetes, typically develops in childhood or adolescence. Symptoms usually appear quickly, often over the course of a few weeks.

Type 2 diabetes, previously known as adult-onset diabetes, most commonly occurs in adults. Symptoms appear gradually and many patients live for long periods without knowing they have the condition at all.

Treatment

Type 1 diabetes is also known as insulin-dependent diabetes because patients must regularly inject insulin into their bodies. There is no cure, and daily blood sugar testing is necessary to monitor and regulate insulin levels.

Type 2 diabetes can be managed and even reversed with a healthy diet and regular exercise. Some patients may also need medications to help their body use insulin effectively.