Learn about the stages of type 1 diabetes and why they are important

T1D develops before you have any symptoms

Thanks to years of dedicated research we now know that people can start developing T1D for more than 15 years before symptoms show. The development of the condition can be split into separate stages.

This chart explains the different stages of T1D and the symptoms that people should be aware of.

What are the stages of type 1 diabetes?

Stage 1

In stage 1, a person has no symptoms and their blood glucose levels are normal, but blood tests show multiple autoantibodies.

Stage 2

Once people move into stage 2, their blood glucose levels begin to fluctuate but they still don’t experience any symptoms.

Stage 1 and 2 T1D are also known as pre-symptomatic, preclinical, or early-stage T1D. This is because, although people in these stages show biological signs of T1D (autoantibodies present in blood), they don’t yet experience the medical symptoms (frequent urination, extreme thirst, unexplained weight loss etc).

Stage 3

Stage 3 is when people begin to develop symptoms of type 1 diabetes: extreme thirst, needing to urinate more frequently, losing weight quickly, and feeling tired.

It is at this point that most people go to the doctor and are diagnosed with ‘clinical’ T1D. This is also when people start on insulin therapy because they can no longer produce enough of their own insulin to keep their blood glucose in a safe range.

Stage 4

Sometimes researchers and clinicians include a fourth stage, which is used to describe people who have lived with T1D for many years, known as long-standing T1D.

At this stage, complications of diabetes are more common as they are caused by repeated high and low blood sugar (hyperglycaemia and hypoglycaemia) over time.

Find out more about type 1 diabetes complications.

Can we delay T1D?

There are a lot of research projects ongoing globally looking at drugs called ‘disease modifying therapies’ or immunotherapies. Researchers aim to use these drugs to halt T1D progression or prevent it in the first place.

Many of these research trials focus on preventing people from moving from stage 1 to stage 3 T1D, essentially stopping the progression in its tracks. Identifying people in these pre-symptomatic stages is essential if they’d like to access clinical trials testing these therapies or use these therapies in the future as they become available. It is also important to allow access to support pre-diagnosis and preventing complications such as diabetic ketoacidosis (DKA) when diagnosed.

Find out more about ongoing research in early detection.

Early detection for T1D

We need early detection programmes to find people in stage one and two T1D because they don’t have any observable symptoms of T1D. This process involves looking for biological signs of the autoimmune attack responsible for T1D in samples of your blood.

There are ongoing testing programmes in the UK to screen for T1D called ELSA and T1DRA. ELSA is available to all children aged two to 17 years old, and T1DRA is available for those aged 18-70. These programmes tests for autoantibodies, and if they are identified this can give the families time to prepare for life with T1D and avoid serious complications like DKA

Find out more about early detection programmes in T1D.

How quickly does someone progress through the stages?

There is no set timeline for the progression of T1D, which is why people in the early stages should be closely monitored to find out when they need to start insulin therapy. The younger you are, the faster you tend to progress through the stages.

Key differences exist between adult and childhood-onset T1D, many of which are not well understood. There is ongoing research into why these differences exist and why T1D may progress slower in some than others, including a publication from Dr Sarah Richardson around why T1D is more aggressive when diagnosed at a younger age. This research was funded by the Type 1 Diabetes Grand Challenge, in partnership with Breakthrough T1D, The Steve Morgan Foundation and Diabetes UK.

This page has been developed by Breakthrough T1D with funding from Sanofi UK and Abbott Diabetes Care who have had no editorial input or control over the contents.