If they feel unwell, people with diabetes need to take special care as any illness, even if not specifically related to their diabetes (like the flu) can cause their blood sugar (glucose) level to rise.

Part of the body's natural response to illness is to raise the circulating blood sugar level. This may mean that people with diabetes need to take a higher dose of insulin than usual, rather than reducing the dose or not taking any.

Reducing an insulin dose or stopping it altogether can lead to serious problems and often may cause Diabetic Ketoacidosis (DKA). This is an emergency state in diabetes which requires hospital based treatment.