Prevention means stopping ill health before it starts. It is split into three different parts that happen at different stages:
This is before there is any ill health – trying to protect healthy people from getting a disease or illness. Immunisation is a good example of Primary Prevention.
This is catching people in the earlier stages of their disease when the symptoms may be reversed. This may require medical intervention, and often involves lifestyle changes e.g. stopping smoking or exercising more to lower high blood pressure.
The control or reduction of an already established disease, when the symptoms cannot be reversed. This often involves medical intervention, and lifestyle changes can be an important part of managing symptoms and living well with the condition.