A medical professional has pinpointed the specific number of alcoholic beverages that can lead to a hangover, shedding light on how swiftly alcohol impacts the brain and nervous system.

Drinking remains a favored pastime in the UK, with a YouGov poll indicating that approximately 82% of the population indulges. Data from 2022 highlights that 6% of British adults enjoy alcohol on a daily basis, and another 4% consume it five to six times per week.

Furthermore, about 14% of people drink on three to four days each week, 23% partake once or twice weekly, while a third (33%) drink less frequently but still partake in alcohol. In light of these figures, Doctor Bhavini Shah, a general practitioner with LloydsPharmacy Online Doctor, offered some advice.

She clarified: “Consuming one or two units of alcohol can increase heart rate, dilate blood vessels, and provide a mild ‘buzz,’ often making individuals feel more sociable or chatty.”

One unit of alcohol equates to 10ml or 8g of pure alcohol, which is roughly the amount an average adult can metabolize in an hour.

The units in a drink vary based on its size and alcohol content. For example, as per NHS guidelines, a pint of strong lager contains three units, whereas a pint of lower-strength lager has slightly more than two units.

Dr Shah continued: “After four to six units, alcohol begins to impact your nervous system, decreasing reaction time and affecting areas of the brain associated with decision making, resulting in poorer judgement and potentially more reckless behaviour.” 

How many drinks lead to a hangover?

She said that consuming around eight units of alcohol typically leads to a hangover. This is equivalent to about four pints of low-strength cider or beer (3.6 per cent) or four standard glasses of wine (175ml).

“After eight units, your vision and sleep will be affected and you will have consumed more alcohol than your liver can process in one night, resulting in a hangover,” Dr Shah said. “And after ten units, your coordination will be highly impaired and you can expect symptoms of nausea, diarrhoea, and vomiting, as well as dehydration and headaches.”

However, regularly consuming eight or more units is considered “binge drinking” for men, while six or more units is considered a binge for women. The NHS advises adults not to regularly drink more than 14 units per week.

The guidance suggests: “Spread your drinking over three or more days if you regularly drink as much as 14 units a week.” Dr Shah highlighted the dangers, saying “after 12 units, you are at great risk of alcohol poisoning.”

How to get rid of alcohol in your system

Dr Shah said: “Your body will metabolise alcohol at its own rate and there is not much evidence that you can speed up this natural process. However, there are steps you can take to reduce the symptoms of your hangover.

“Going to sleep is a good way to let your body naturally remove alcohol from your system by itself. Drinking water is also essential as it will prevent the dehydrating effects of the alcohol and reduce the impact of headaches.”

Eating the right foods is key too, with the doctor suggesting, “you should also try to eat bland foods as these will increase your blood sugar without upsetting your stomach.”

For advice on cutting back on alcohol, visit the NHS website here.