Young people should be given advice on the dangers of alcohol when they access sexual health services, a group of health experts has recommended.
The Alcohol and Sexual Health Working Party says the NHS is missing "key opportunities" to tackle the problem.
It suggests alcohol and sexual risk-taking go hand-in-hand.
Meanwhile, government advisers say everyone should be asked about their diet, smoking and drinking habits every time they see a health professional.
The Alcohol and Sexual Health Working Party was created by the Royal College of Physicians, supported by the British Association for Sexual Health and HIV (BASHH).
Its report says more than 1.5 million young people attend clinics dealing in sexually-transmitted infections (STIs) every year, and surveys suggest one in five attendees consume dangerous levels of alcohol.
"STIs mostly affect young persons under the age of 25 years, and 16 to 24-year-olds are among the highest consumers of alcohol," the report says.
"People who drink hazardously are more likely to have multiple partners, thus increasing the risk of acquiring an STI."
The study notes consumption of higher-strength alcoholic drinks has increased, particularly among girls. While men still consume more alcohol than women, young women are more likely to report feeling drunk.
It added: "Earlier alcohol use is associated with early onset of sexual activity and is a marker of later sexual risk-taking, including lack of condom use, multiple sexual partners, sexually-transmitted infection and teenage pregnancy."
In a sample of more than 2,000 15-to-16-year-olds from the UK, 11% regretted having sex under the influence of alcohol, the report said. Some 82% of 16 to 30-year-olds also report drinking alcohol before sexual activity.
Dr Simon Barton, chair of the working party, wants the government "to support commissioning arrangements" so trained health professionals can challenge behaviour in that "reflective moment" when someone comes to a sexual health clinic asking why something has happened to them.
"Often the conversation is about excusing behaviours - just the language which is used, 'I got off my face, I got wasted.' It was if it was happening to them passively," he told BBC Radio 4's Today programme.
"We are trying to ensure they reflect on their behaviour."
Dr Barton said failing to discuss alcohol consumption with a patient accessing sexual health services was a missed opportunity.
"At a time when the NHS is looking to save £20bn, this is a perfect example of quick-win efficiency that could save money in the long term," he added.
The report - Alcohol and sex: a cocktail for poor sexual health - says all clinicians providing sexual health services should be trained in asking about drinking habits. Patients should also be referred for further support if they need it.
Dr Janet Wilson, president-elect of BASHH, said: "Everyone knows that alcohol fuels risky sex - so a sexual health check-up is the ideal time to broach the subject."
The NHS Future Forum, which advises the government on its health reforms, wants all healthcare professionals - from doctors and nurses to physiotherapists and pharmacists - to raise lifestyle issues as a matter of routine.
Prof Steve Field, head of the independent body, told the Guardian: "In future if you come for your flu vaccine at a GP's surgery or pharmacy, the health professional should give you your injection but also use the opportunity to talk to you about your diet, smoking, alcohol intake and how much exercise you're taking, discuss any anxieties you may have about these, and offer advice and support."
The forum's call to make "every contact count" is the centrepiece of a report commissioned by Health Secretary Andrew Lansley, and due to be published next month.