The alcohol is carried in the blood to other parts of the body. The highest concentrations of alcohol are found in the brain, liver, heart, kidneys and muscles.

The amount of alcohol in someone's blood is measured by their BAC (blood alcohol concentration). BAC is usually measured as the number of milligrams (mg) of alcohol in 100 millilitres (ml) of blood. It increases significantly if someone has drunk more alcohol than their body can get rid of. But you can't measure your BAC accurately by the number of drinks you’ve had, even if you know how much alcohol you have drunk. That's because the BAC depends on so many things - including your size and weight, your gender, what kind of drink you've had and whether you've eaten anything first.