The needles used to inject insulin are very small as the insulin only needs to be injected under the skin (subcutaneously) – not into a muscle or vein. Once it's been injected, it soaks into small blood vessels and is taken into the bloodstream.

Injections can be a little painful, especially the first few because you may be feeling tense. As your confidence grows and you become more relaxed they will get easier and soon become second nature.

There are three main areas where you can inject insulin – stomach, buttocks and thighs. Sometimes your healthcare team may recommend other sites such as your arms. As all these areas cover a wide skin area you should inject at different sites within each of them. It is important to rotate injection sites, as injecting into the same site can cause a build-up of lumps under the skin (also known as lipohypertrophy), which may lead to erratic absorption of the insulin which will affect control of blood glucose levels.

Reviewed August 2009