The effects of these symptoms will usually be more extreme, the higher blood sugar levels someone has. They therefore tend to be pronounced in children and young people with type 1 diabetes, whilst people with undiagnosed type 2 diabetes may have initially subtle symptoms that become more pronounced over a gradual period of time.

What are the big 3 signs of diabetes?

Three of the main signs of diabetes are:

Whilst these are 3 of the most common symptoms of diabetes, other symptoms may also, or instead, be present.

For a more exhaustive list see symptoms of diabetes.


If you’re needing to frequently go to the toilet and are therefore passing a lot of urine, this is called polyuria.

If you’re needing to urinate more often than usual at night, or through the day, this may be a sign of high blood glucose levels and diabetes, particularly if it’s accompanied by a relatively strong thirst.


Polydipsia is the term for excessive thirst. People with undiagnosed diabetes may become significantly more thirsty than usual as a result of having high blood sugar levels.

This increased thirst may cause you to drink two glasses or mugs of water one after another or drink straight from the tap if you wouldn’t normally do this.


Another one of the key signs of diabetes is polyphagia, or increased appetite.

Diabetes makes it harder for the body to get energy, in the form of glucose, out of the blood and into the cells that need the energy. This means that if people with undiagnosed, or untreated, diabetes have too high sugar levels and eat, it can make them more rather than less hungry.

Diagnosing diabetes

If you notice the symptoms of diabetes, don’t be tempted to wait to see if the symptoms disappear or become more pronounced as untreated diabetes can become dangerous or cause lasting damage to parts of the body, such as the nerves and eyes.

If you recognize the symptoms of diabetes, arrange to be tested for diabetes by your doctor. Read more on diagnosing diabetes.