In general, people with diabetes either have a total lack of insulin (type 1 diabetes) or they have too little insulin or cannot use insulin effectively (type 2 diabetes).

Type 1 diabetes (formerly called juvenile-onset or insulin-dependent diabetes), accounts for 5 to 10 out of 100 people who have diabetes. In type 1 diabetes, the body’s immune system destroys the cells that release insulin, eventually eliminating insulin production from the body. Without insulin, cells cannot absorb sugar (glucose), which they need to produce energy.

Type 2 diabetes (formerly called adult-onset or non-insulin-dependent diabetes) can develop at any age. It most commonly becomes apparent during adulthood. But type 2 diabetes in children is rising. Type 2 diabetes accounts for the vast majority of people who have diabetes-90 to 95 out of 100 people. In type 2 diabetes, the body isn’t able to use insulin the right way. This is called insulin resistance. As type 2 diabetes gets worse, the pancreas may make less and less insulin. This is called insulin deficiency.

How are these diseases different?

Type 1 diabetes

Often diagnosed in childhood

Not associated with excess body weight

Often associated with higher than normal ketone levels at diagnosis

Treated with insulin injections or insulin pump

Cannot be controlled without taking insulin

Type 2 diabetes

Usually diagnosed in over 30 year olds

Often associated with excess body weight

Often associated with high blood pressure and/or cholesterol levels at diagnosis

Is usually treated initially without medication or with tablets

Sometimes possible to come off diabetes medication

How are they alike?

Both types of diabetes greatly increase a person’s risk for a range of serious complications. Although monitoring and managing the disease can prevent complications, diabetes remains the leading cause of blindness and kidney failure. It also continues to be a critical risk factor for heart disease, stroke, and foot or leg amputations.

Are the Symptoms of Diabetes Different?

The first symptoms of type 1 diabetes appear when blood sugar gets too high. Symptoms include thirst, hunger, fatigue, frequent urination, weight loss, tingling or numbness in the feet, and blurred vision. Very high blood sugar can cause rapid breathing, dry skin, fruity breath, and nausea.

Meanwhile, the first symptoms of type 2 diabetes may not show up for many years — meaning the disease can ravage a person’s body without them realizing it. Early symptoms include frequent infections, fatigue, frequent urination, thirst, hunger, blurred vision, erectile dysfunction in men, and pain or numbness in the hands or feet. Drincic notes that “symptoms of type 2 diabetes don’t start as suddenly as symptoms of type 1 diabetes.”

Is Diagnosing Diabetes Types 1 and 2 Similar?

Blood tests used to diagnose type 1 and type 2 diabetes include fasting blood sugar, a hemoglobin A1C test, and a glucose tolerance test. The A1C test measures the average blood sugar level over the past few months. The glucose tolerance test measures blood sugar after a sugary drink is given.

The blood sugar testing to diagnose and manage type 1 diabetes is very similar to the testing for type 2 diabetes. A blood test can be done that looks for antibodies to detect if it is type 1 or 2. In type 1 diabetes, the immune system makes antibodies that act against the cells in the pancreas that make insulin, and these antibodies can be detected in a blood test. Your doctor may suspect type 2 diabetes based on your symptoms and risk factors, such as obesity and family history.