How does autoimmune type 1 diabetes work?

Autoimmune type 1 diabetes is a condition where the immune system mistakenly attacks insulin-producing beta cells in the pancreas.³ It is often linked to genetics and is not directly linked to diet or lifestyle.⁴ While certain factors like genetics or the environment may play a role, it can affect people of any age, including children, teens, and adults.³

Autoimmunity happens when the immune system mistakenly attacks the body’s own healthy cells. Instead of responding to viruses or bacteria, the immune system produces autoantibodies that target parts of the body, such as the insulin-producing beta cells in the pancreas.⁵

These beta cells aren’t harmful, but the immune system mistakenly sees them as threats and tries to destroy them.³

In autoimmune type 1 diabetes, the body makes certain substances called autoantibodies that target the beta cells and mark them for destruction.

While these autoantibodies aren’t what destroy the beta cells, their presence is a sign of the autoimmune attack.³ As these cells are lost, the body becomes less able to produce insulin naturally.⁶

Testing for these autoantibodies through screening is therefore valuable to identify people with an increased chance of developing autoimmune type 1 diabetes, even before symptoms appear.³

Insulin is a hormone made by the pancreas. It helps move glucose from the food we eat into the body’s cells, where it is used for energy. When the pancreas is working properly, insulin helps keep glucose levels balanced throughout the day.⁷

Without enough insulin, glucose can’t enter the cells as it should. Instead, it starts to build up in the bloodstream, which leads to irregularly high glucose levels.⁷ This buildup means that, even though there’s glucose in the blood, the cells can’t use it effectively for energy.⁷

When the body doesn’t have enough insulin, it can’t move glucose from the blood into the cells where it’s needed for energy. To make up for this, the body starts breaking down fat stores for fuel instead. This process releases substances called ketones.⁸

But in people with autoimmune type 1 diabetes, this shift can quickly become harmful. Without insulin to keep things in balance, fat breakdown speeds up, and ketones begin to build up in the blood. At the same time, the body’s ability to clear ketones is reduced.⁸

If ketone levels become too high, it can lead to diabetic ketoacidosis (DKA), which is a medical emergency. However, early detection through screening can help track the progression of autoimmune type 1 diabetes and reduce the likelihood of starting the journey with a medical emergency.⁸

Unlike some other cells in the body, insulin-producing beta cells don’t regenerate once they’ve been destroyed.⁹

Adding to this challenge, the immune system doesn’t stop attacking beta cells after the disease starts. This ongoing immune activity makes it impossible for the pancreas to recover or repair itself.⁹

As such, unlike type 2 diabetes or prediabetes, autoimmune type 1 diabetes is considered irreversible and can’t be reversed through diet, exercise, or other lifestyle changes.⁴ As a result, people with autoimmune type 1 diabetes need to replace the missing insulin every day, either through injections or an insulin pump, to keep their glucose levels in a safe range.¹ Uncover other common myths around autoimmune type 1 diabetes.

Autoimmune type 1 diabetes develops over time. Early-stage autoimmune type 1 diabetes is when the immune system mistakenly starts attacking the insulin-producing beta cells in the pancreas, but symptoms are not present, otherwise known as presymptomatic autoimmune type 1 diabetes (Stage 1 or 2). In the later, clinical stage of autoimmune type 1 diabetes, known as symptomatic autoimmune type 1 diabetes (Stage 3), symptoms appear, and insulin production is significantly affected.¹

While symptoms don’t emerge until later, we can now detect autoimmune type 1 diabetes early through screening. This is done through a simple blood test that looks for autoantibodies.³

Learn more about the screening process.

Understanding that autoimmune type 1 diabetes develops in stages allows for better planning.¹⁰ By tracking how glucose levels and insulin production change over time, healthcare professionals can decide when insulin therapy might be needed.¹¹

If autoimmune type 1 diabetes runs in your family, or if someone has another autoimmune condition like thyroid disease (including Hashimoto’s thyroiditis or Graves’ disease) or celiac disease, it’s a good idea to talk to your doctor about screening.¹² Detecting the condition early can reduce the chance of a medical emergency.¹

Calculate your risk of autoimmune type 1 diabetes.