A horrible reminder of the night before. Typical symptoms include a pounding headache, raging thirst, depression, and feeling sick. You can also be more sensitive to noise and bright lights.

So what causes a hangover? It's partly alcohol's diuretic effect, which makes the body lose too much water and causes dehydration. It can also be the effect of congeners - naturally occurring substances in alcoholic drinks, some of which are toxic. Generally, clear or lighter coloured drinks like vodka contain fewer congeners than darker coloured drinks like red wine or port.

A hangover is simply nature's way of telling you that you've overdone it, and if you have, we've some tips for the morning after .