By Natasha Courtenay-Smith, Telegraph.co.uk

They're smart, successful professionals who never miss a day's work - the very opposite of the image of the problem drinker. Natasha Courtenay-Smith meets three upright young women who thought alcoholism would never happen to them

Before she fell pregnant in 2000 Olivia McMahon had a reputation as a bit of a party girl. On a night out she was always the first to the bar and the last to leave, and was proud of her ability to throw back more tequila shots than any of her peers.

'I was always up for getting really drunk - I had been since my teens,' says Olivia, now 37, a successful food photographer.

'I didn't think I was any different to my friends or my husband. We all liked socialising and having a good time, and I wouldn't have even considered that any of us was drinking too much. Yes, I did throw up from time to time, and suffered from memory loss after a big night out, but doesn't everyone? I could still drag myself into work in the morning, even if I did have a stinking headache, so I couldn't see what the problem was.'

Even when, following the birth of her daughter Chloe, Olivia began to drink during the day, too, she wasn't concerned about the amount of alcohol she was consuming.

'I had a few friends with babies of the same age, and we'd all get together for lunch, during which I'd inevitably crack open a bottle of wine,' she recalls.

'I'd end up plastered by 3pm, and would open another bottle of wine in the evening when my husband got back from work. The last thing on my mind was that I had a problem - I was just making the most of my maternity leave. I'd stopped breast-feeding by then, so I wasn't worried about my daughter.'

Olivia's case may be extreme but these days she is far from alone.

According to the Office for National Statistics, almost a quarter of adult women report drinking five days or more per week, and recent NHS figures state that a fifth of women drink more than the recommended number of units at least once a week.

Even those of us who have grown out of excessive bouts of binge drinking seem to have a bottle of wine permanently chilling in our fridges and think nothing of pouring ourselves a large glass to accompany our dinner.

Yet how many of us realise that alcohol affects women's bodies differently to men's, and can increase our risk of cancer, digestive problems and coronary heart disease?

The number of women in Britain dying from drinking has almost doubled since 1991 to just under 3,000 in 2005, with women aged between 35 and 54 the fastest-growing group of victims.

High-profile deaths related to alcohol include Sally Clark, the solicitor wrongly jailed for murdering her two sons, and the ex-MP Fiona Jones, who died last year aged 49. She turned to drink to deal with the stress of working in the House of Commons and slid into full-blown alcoholism after losing her seat in 2001.

For Olivia, returning to work meant that her drinking escalated. 'I was being pulled in so many different directions that I couldn't do anything properly, and alcohol was the only way I knew to relieve the stress,' she says.

'We'd often have bottles of wine and champagne on photo-shoots, and I'd have a glass while I was working. No one said anything as they all thought I was just game for a laugh. At home I drank more than ever, too. I could easily polish off a bottle of wine on my own, and would frequently have a third of a second bottle as well.'

By the time Chloe was two Olivia was out every night drinking heavily with friends, while her husband looked after their daughter. He eventually kicked her out of the family home. Still, when he insisted she had a problem she wouldn't listen. 'In my mind I didn't fit the mould of the alcoholic. I didn't keep vodka in my sock drawer and I didn't drink first thing in the morning.'

So how much alcohol is too much? The Department of Health recommends that women drink no more than 14 units of alcohol a week, and no more than three units in any one day (a 175ml glass of wine at 13 per cent is 2.3 units; a measure of spirits is one unit).

After an episode of heavy drinking it is advised that you refrain from drinking for 48 hours to allow the body to recover. But William Shanahan, the medical director at the Capio Nightingale clinic, which offers treatment for addiction problems, says such guidelines are confusing.

It is not possible to state, he says, a single tipping point at which heavy drinking can be called alcoholism. 'It's important to remember that all alcohol is a poison, and that our bodies are only able to metabolise one unit an hour,' he says.

'Anything over that will damage your body. Most people hate the term "alcoholic" because they don't see themselves sitting on Hungerford Bridge with a brown paper bag. It's much more helpful to think of it in terms of "harmful drinking" and "dependent drinking" rather than simply as alcoholism.

'Drinking is harmful if it causes a problem in any area of your life. If, for example, your character changes for the worse after a few glasses of wine, you might not be dependent on alcohol but there is a problem and you do need to look at the way you drink. If it affects your work, leads you to have unsafe sex or results in mental problems such as depression, you definitely need help.

'Dependent drinkers find that life is not possible without a drink, and they also experience withdrawal symptoms or cravings for alcohol. This is equally a problem that needs medical help.'

Continued: Telegraph.co.uk 17/02/2008