Receiving a diabetes diagnosis can be bittersweet. You may feel anxious and scared about what lies ahead and relieved knowing you’ll be connected with the right treatment. But what if the diagnosis isn’t spot on and the treatment doesn’t seem to be helping you in the long term? That’s what can happen for people with type 1.5 diabetes—a form of diabetes that’s sometimes overlooked or misidentified.

Clinically known as latent autoimmune diabetes in adults (LADA), this condition often looks a lot like type 2 diabetes, especially in its earlier stages. But in reality, it’s an autoimmune disease that eventually requires insulin, just like type 1 diabetes.

Because LADA usually appears in adulthood and develops gradually, many people with the condition are misdiagnosed with type 2 diabetes, which is a big problem that can delay the right treatment. Oral medications and lifestyle changes like diet and exercise that are typically prescribed to treat type 2 diabetes may not bring the improvements doctors expect to see, all the while the immune system continues to gradually attack cells in the pancreas that produce insulin. As a result, blood sugar isn’t in control and the body undergoes further harm.

Different types of diabetes require different treatment approaches, so getting the right diagnosis matters. Here’s what you should know about this condition, how it impacts the body, and why a proper diagnosis is so important.

How is LADA different from other types of diabetes?

To understand LADA, it’s helpful to understand how type 1 and type 2 diabetes work.

Type 1 diabetes is an autoimmune condition where the pancreas either makes very little insulin or no insulin because the immune system attacks important cells in the pancreas that produce insulin. Without insulin, blood sugar builds up in the bloodstream, often causing sharp spikes in blood sugar. People with this form of diabetes have to take insulin each day to survive. It can happen at any age, but typically develops in children or young adults.

“It’s an autoimmune condition where you have antibodies that attack the pancreatic beta cells— the cells that make insulin—and they destroy those cells,” Rozalina McCoy, MD, associate division chief for clinical research, Division of Endocrinology, Diabetes, and Nutrition at the University of Maryland School of Medicine tells SELF. “That is what causes insulin deficiency.”

Type 2 diabetes is a chronic condition where the body still produces insulin, but has trouble using it properly—this is known as insulin resistance and causes high blood sugar. “If your insulin doesn’t work as well, the glucose can’t get from the blood into the cells as efficiently, so blood sugar rises,” Dr. McCoy says. “This pathway is what leads to type 2 diabetes.”