Type 1 diabetes

Also called Insulin-dependent diabetes or T1D

Type 1 diabetes is a lifelong condition where the immune system destroys the cells in the pancreas that make insulin, the hormone that controls blood sugar. Without insulin, blood sugar levels become too high. It often starts in childhood or young adulthood but can begin at any age. It is not caused by lifestyle.

Last updated Nov 9, 2026

What it is

It is managed with insulin injections or a pump, checking blood sugar with finger-prick tests or a sensor, and adjusting insulin to food and activity.

Regular checks of the eyes, feet, kidneys and HbA1c help prevent complications. Diabetes teams and education courses support people to manage it.

Common signs

  • Feeling very thirsty
  • Peeing more than usual, especially at night
  • Feeling very tired
  • Losing weight without trying
  • Blurred vision
  • Thrush that keeps coming back

How it is usually diagnosed

  • Blood sugar tests
  • HbA1c
  • Tests for ketones
  • Sometimes antibody tests

Records worth keeping

Keeping these together makes each appointment easier, especially when you see a new doctor:

  • HbA1c results over time
  • Glucose sensor or meter reports
  • Diabetes clinic letters
  • Eye screening and foot check records
  • Insulin doses and plans

Questions to ask your doctor

  • What should my blood sugar targets be?
  • Would a pump or sensor suit me?
  • What should I do when I am ill?

When to get help right away

Call 112 or go to the nearest emergency department if you have:

  • Vomiting, tummy pain, fast breathing, confusion or high ketones: call 112
  • Low blood sugar that does not improve after treatment or causes unconsciousness: call 112

This page is general information. It is not a diagnosis and does not replace a doctor who knows your history. Medfold keeps your records organised; it does not interpret them.

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