If someone does not produce enough insulin to control their blood glucose concentration they have diabetes.


  • Glucose in the urine – blood glucose concentration is so high that some is filtered out by the kidneys and passed into the urine
  • High blood glucose levels
  • Being thirsty
  • The need to go to the toilet a lot
  • Lethargy – feeling tired/having low energy
Type 1 diabetesType 2 diabetes
DevelopsIn childhood.In older people (a progressive disease linked to poor diet/lack of exercise/obesity).
EffectPancreas stops producing insulin.Pancreas gradually produces less insulin. Insulin not as effective.
TreatmentControl carbohydrate intake.Control carbohydrate intake and increase exercise in order to lose weight.
Injection of insulin.Tablets.
Injection of insulin.
FutureIncrease in numbers of sufferers due to an increase in obesity. Becoming more common in young people.
A diabetes sufferer injecting insulin.


If too much insulin is injected or not enough food is eaten regularly, the blood glucose concentration can drop too low and a hypoglycaemic attack (a ‘hypo’) may occur, resulting in unconsciousness/coma.

If blood glucose concentrations remain too high over a long period (if the individual has been diabetic for a long time or their diabetes is undiagnosed or uncontrolled), serious long-term effects can arise.

Long-term effects

  • Eye damage/blindness
  • Heart disease
  • Stroke
  • Kidney damage

These complications are due to high blood glucose concentrations damaging the capillaries that supply that part of the body.