If you smoke while drinking a lot of alcohol it may make your hangover worse than it should be, according to new US research.

Research carried out on 113 students found that those who smoked while drinking had worse hangovers than those who drank without smoking.

The researchers asked the students to keep a diary for eight weeks, recording their drinking and smoking and any 'morning after the night before' symptoms.

It was found that when the students drank a lot - around six cans of beer in an hour - those who smoked at the same time suffered a worse hangover. 

The scientists don't know for sure what causes cigarettes to worsen hangovers, but they suggest there is some direct effect of smoking on the body while alcohol is being drunk. This may be due to the pharmacological effects of nicotine on the nervous system.

The study is published in the Journal of Studies on Alcohol and Drugs.