People who drink regularly become less affected by alcohol as their bodies get used to it. They then need to drink more for it to have the same effect. This is called developing a tolerance to alcohol.

Although people who've developed high tolerance may not feel drunk, they still run a serious risk of damaging their health .

If you're worried about your own or someone else's drinking, you can call this free helpline, in complete confidence. They can put you in touch with your local alcohol advice centre for help and advice. Call Drinkline on 0800 917 8282 (open 24 hours)