I am of the pre-Jordan generation. Until recently, it never occurred to me that bigger breasts were something you could choose, still less that ageing was a process over which you might be expected to exercise any control. The idea of cosmetic surgery was remote and unthinkable.

And it was obviously not for the likes of me. Increasingly, though, plastic surgery seems to be for everyone: ubiquitous and taken for granted. Film directors claim that everyone in Hollywood has had Botox and eyelid surgery (even those who say they haven't), with the result that Emma Thompson is the only actress who can still raise her eyebrows. There is something on television about cosmetic surgery every day (Nip/Tuck, Extreme Makeover, interminable items on Living TV). And advertisements on my bus into work are currently offering loans for liposuction from Abbey, an institution that has had an extreme makeover of its own and is also pushing money for nose jobs.

I am starting to get worried by this. I have always looked younger than I am, which engendered a lovely fantasy that I really was younger. But many people who once looked comfortingly older than I now appear to have gone into reverse. Martha Stewart turned up to her trial with the face of a peachy young homemaker. Roseanne has spent $60,000 on new eyelids, cheek implants, liposuction, a facelift, a nose job, a chin implant, a breast reduction and tummy tuck and is now, effectively, an entirely different person. Sharon Osbourne has had a 'tummy tuck, body lift, lipo on my hips, butt lift, thigh lift, facelift, eyelid lift, breast lift' and is such an evangelist for enhancements that she had her last round of Botox injections on television.

And it's not just older people. Madonna, who is roughly my age, is rumoured to have had a facelift, though her publicist has denied it. Victoria Beckham, who is a good bit younger, has absurdly pert and luscious breasts for such a thin person ('Biologically very unusual,' one doctor told me), especially one who has also had two children.

Of course, these women are a) all celebrities and b) absurdly rich. But their function is partly to set standards the rest of us are supposed to aspire to, however vainly. What worries me about cosmetic surgery is that it might reach a tipping point; it might become like cosmetics, hair dye or straight teeth, things that people once lived comfortably without but which are now almost required, so that you look actively odd if you don't make the best of yourself in the prescribed lipsticked and orthodontic ways. What worries me is that if I want to carry on looking and, more importantly, feeling young, I might have to have it.

Before the rise of the mass-market cosmetics industry in the 1920s, face-painting was deplored as a kind of deception; today, there can hardly be a woman in the Western world who doesn't own a make-up bag. Between the 1950s and the 1970s, the percentage of American women dyeing their hair went from 7 per cent to 40 per cent. Now, it's unusual not to rush for the tinting lotion at the first hint of grey. There could very soon become a similarly coercive aspect to cosmetic cutting and slicing, lifting, sucking and sewing.

'The aim is to pull the skin and the SMAS [a layer of tissue and muscle under the skin called the superficial musculo-aponeurotic system] attached to it upwards,' write the authors of Plastic Fantastic: A Guide to Cosmetic Surgery, explaining a facelift. 'Muscles in the lower face and neck are tightened and anchored to bone with stitches where possible. Skin is then redraped over more youthful contours.' This makes me feel queasy just reading about it; I am hoping the tipping point is safely postponed until I'm too old to care.

I worry that my generation is being required to normalise cosmetic surgery, to accept it as another weapon in our arsenal of ever-youthful attractiveness, at a time when the benefits are not proven to be commensurate with the risks. These are definitely greater than the cosy nipping and tucking metaphors imply. In January, novelist Olivia Goldsmith, author of The First Wives Club, died during an operation for a chin tuck. Earlier this month, Lorraine Batt's family were awarded compensation for her death in a north London hospital following a tummy tuck. Deaths from liposuction operations in the US are running at 20 per 100,000, according to research carried out by the plastic surgeon Frederick Glazer, vastly higher than deaths from, say, hernia operations (also an elective procedure) at three in 100,000.

So is it the danger that puts me off? Or is it simply that the procedures still haven't yet been sufficiently 'democratised', in the favoured formulation of plastic surgeons? Or perhaps it's just that I don't think I need it yet.

Here, though, I may well be alone. In an effort to find out more about cosmetic surgery, I booked three appointments at the sort of clinics that advertise in the back of glossy magazines. Everyone I saw thought I needed work. Unfortunately, they all thought I needed something different. It seems that there's nothing right with my face, nothing that wouldn't benefit from an incision here or an injection there.

My first call was at the Transform Clinic in Wimpole Street. This happens to be located in the same building as my children's dentist: I scurried past her door, terrified she might poke her head out and ask me what on earth I was doing there. The waiting room was busy. A pair of friends had come along together, rather as I remember girls going to family planning clinics in the 1970s. I filled in a couple of forms before being taken into a plush, chintzy room where I was seen by Josephine, a nurse and the deputy clinic manager.

I remarked on how busy they were. 'We've been frantic with people wanting pouts for Valentine's Day,' Josephine said, in a comforting, soft, Irish accent, touching my knee reassuringly. 'We've had women crying in the waiting room because they couldn't get in for an appointment.'

Josephine said I needed Perlane, a collagen-like substance to pad out my mouth, plus Botox, because I have forehead lines. I had never even thought about forehead lines before; this is a whole new anxiety she has introduced into my life. 'You raise your eyebrows all the time when you're talking,' she said. That, I want to tell her, is what they're for.

She tried, effortfully, to raise her own eyebrows and only succeeded in making a different kind of funny face, one that doesn't involve creases. 'And I am a year older than you,' she said, as if there were something competitive about it. I replied politely that she looked fabulous, which she did, but secretly, I was surprised. I had been thinking of her as much older, and this, I realise, is to do with our roles. She was acting maternal and kindly and I was acting a bit dim and useless.

Perlane and Botox together would cost £841 and both would need redoing in a few months. The Botox, Josephine said, would take 72 hours to work: 'But it's a very good 72 hours: you keep looking in the mirror and you can't stop pointing it out to your husband.'

I suspect if I kept pointing out lines on my forehead to my husband, he might develop a pressing need to go out. But perhaps I am the only person who has never thought about forehead lines. Perhaps everybody else thinks about them all the time. For some weeks afterwards, I watch television mainly to see whether other people have them. (Everyone at the Oscars is suspiciously forehead line-free.) In this way, I miss numerous important items of news.

Romaine Da Silva has had two lots of liposuction - one on her inner and outer thighs, lower abdomen and bottom, the other on her upper body. She runs the Tanning Studio in East Sheen and admits: 'I am not dedicated when it comes to gyms and dieting. I'd love to be the girl who runs eight miles every evening. But I don't have the discipline. So why not have the body you want, if you can have it another way? I spent about £10,000 and I swear it's the best thing I ever did.

'After I got married, I went on a bit of a downer. It was like, "OK, it's over now - I've found the man, done the business." I just sat at home and ate. I had the lower half done first and then a few years later I was wearing size 10 jeans with 14 tops. I had really chubby arms. I had half a litre out of each arm. Now I have defined muscles and I don't have a roll of fat above and below my bra strap. I tell everyone I've had liposuction. I felt like a lump before. I'm not ashamed of it.'

Romaine exposes several of the reasons I am suspicious of cosmetic surgery, and they have to do with pretty straightforward feminism. I don't think women should conceive of their lives as finished once they are married; nor that food should be the enemy; nor that physical attractiveness should seem to be all we have to offer. As I get old, I would like to be valued for all sorts of interesting things. There ought to be a space in which women can operate and feel important that has nothing to do with having had fat siphoned out of our bottoms and injected back into our faces. And if there isn't, then we should demand it.

I'm not suggesting there are any easy answers. American feminist Kathryn Morgan has urged women to protest by pulling down our breasts, dyeing our hair grey and generally 'revalourising' ugliness. Apart from the fact that this simply substitutes one prescription for another, her strategy would exacerbate the problem by affirming that how we look matters more than anything else. Cosmetic surgery is a kind of political defeatism, a recognition that it's easier to change oneself than change the world. (The first group of Americans to seek out cosmetic surgery in large numbers were Jews unhappy with their noses. Then, through the 1950s, they were joined by Italians, Greeks, Armenians and Iranians, who were anxious not to look Jewish.)

I am, though, in no position to take the high ground here. Like Romaine, I am fond of a toned tricep. And I am not sure that the fact that I get mine by occasionally lifting weights makes me any more noble. The means may differ, but the ends are the same.

My second appointment is at the London Centre for Aesthetic Surgery, where I am seeing Maurizio Viel. Photographs of Maurizio and Roberto, his twin brother, looking identically suave and sexy in their surgical scrubs, are distributed around the waiting room. I fill in my form underneath a framed letter certifying that the Viel brothers attended the 1994 meeting of the American Society for Aesthetic Plastic Surgery at the Loews Anatole Hotel, Dallas.

I am slightly perplexed by this: the largest and most influential professional organisation for the specialism in the US is called the American Society of Plastic and Reconstructive Surgeons. I have also heard of an American Board of Plastic Surgery and the American Association of Plastic Surgeons. But this other one is new to me.

The Viels's glossy brochure, which refers to injections 'of botulunum' and to 'pearlane', says the brothers are 'fully qualified surgeons with international certification in cosmetic surgery'. When I call to find out what this means, a woman in the office says they 'have got loads of certificates. They're all over the office. They qualified in Italy and have been here for 15 years. No one's ever asked this before.' (Another doctor tells me despairingly that women spend more time choosing a pair of shoes than selecting a cosmetic surgeon.)

Any doctor can set up as a cosmetic specialist in this country. It is thought that 60-70 per cent of all cosmetic surgery here is carried out by those who are not members of the British Association of Aesthetic Plastic Surgeons, BAAPS, and whose qualifications can consequently vary wildly. (BAAPS's 160 members are all either current or former consultant plastic surgeons with an NHS Trust, so have at least had to compete for their positions.)

Maurizio is unlike any doctor I've seen for a long while, nothing like my GP, in her jeans, or the hard-pressed shirtsleeved junior registrars in our local children's casualty department. He wears an immaculate suit, writes with a fat silver fountain pen and resembles someone out of a doctors and nurses romance, circa 1960. He has no forehead lines. Maurizio says I could do with a thread lift, which would involve, as far as I can make out, inserting threads in my temples and pulling them tight. This would apparently pull my face up. I am not clear how this works and the leaflet he gives me doesn't explain it either. But he shows me the effect with his fingers in front of a mirror.

The thread lift would cost £3,000 but at least it wouldn't need doing for another seven years. I could do with some Botox as well, he adds, which would be another £250-£350 a time. 'You cannot expect the same results from this technique as from other more effective surgery,' explains the piece of paper about the thread lift that I am given as I leave. 'However the suggestion for carrying out this technique is simple, carried out under local anaesthetic, and that you leave the clinic at the end, leaving few or no scars and rapidly resume your normal life.' Call me old-fashioned, but you'd think at £120 a consultation they could afford someone literate to write their leaflets.

I am so depressed by this appointment. I have to buy a T-shirt (£8 from Zara: cheaper than Botox, which seems to do the trick). I'm disappointed that no one has yet asked me whether I really think I need surgery and injections or whether the rather generalised dissatisfaction I have expressed might, if they were to sort out the forehead lines, simply move elsewhere. No one has probed my deliberately thin story at all.

They're in business, of course, and they probably calculate that any patients they put off will simply go elsewhere. (BAAPS member Simon Withy does, however, claim he sends away 15- 20 per cent of the people who come to him.) But their reluctance to question motives may also have something to do with the history of cosmetic surgery.

According to Elizabeth Haiken, author of a history of the specialism, Venus Envy, cosmetic surgery took off in the middle years of the last century partly as the result of growing awareness that appearance was an economic matter. Reconstruction work became acceptable for wounded soldiers on the grounds that they needed to support their families. And if appearance was so crucial for them, why not for a single woman, a widow or a homemaker who needed to keep her job, ie her husband?

At the same time, Haiken explains, Alfred Adler's concept of the inferiority complex was gripping a world newly interested in psychiatry. The inferiority complex may have been a vague term, but it was still easier to get hold of, somehow, than Freud's mysterious psychoanalysis, which seemed rather depressing and overly concerned with sex. The inferiority complex became so much the rage that America women's magazines could run features asking 'How's Your IC?' and expect to be understood.

The degree of inferiority and, by extension, of economic incapacity felt by people wanting plastic surgery had to be gauged by patients themselves: it was both subjective and relative. From the cosmetic surgeons' point of view, that was a good thing, because it released them from the necessity of choosing between deserving and undeserving cases. Plastic surgery became psychiatry with a scalpel.

Today, although the NHS does still attempt to make a distinction (no aesthetic surgery of any kind on the taxpayer), many private patients report feeling psychologically transformed after surgery. Simon Withy, who spends four-fifths of his time in the NHS, says that when his private patients leave feeling good, he doesn't think he's any different morally from someone who puts on a theatrical production or writes a book or sells clothes. He's in the business of making people's lives happier, and that seems respectable enough.

As soon as you start trying to judge whether cosmetic surgery is justified, you run into trouble. Elise, a lecturer, had eyelid surgery after oedema (swelling) which she had developed during pregnancy left her with drooping eyelids. The left lid was so badly affected it was hanging on to the eye and twitching. She could have had this fixed on the NHS, but opted to have both eyes done privately. It was a difficult operation because of the fluid that had built up over the years, and eight years later she decided to get a repair at the cost of £2,000. She has been surprised by people's reactions.

'People are quite judgmental. If there's a cosmetic element, everyone's got a view. One of my friends said, "What a terrible waste of money." I wouldn't dream of saying to her that she shouldn't have a people carrier now that her children have grown up. It awakes some atavistic hostility - people don't like to think you're buying your way out of the competition.'

No one can be sure what another person's psychic experience is like - how wretched they might be made by their appearance, how happy they might be if it were transformed. The corollary of that, though, is that cosmetic surgery is available - no questions asked - to anyone with a vague sense of feeling rotten at work and a valid credit card.

My third appointment is at one of the clinics belonging to the Harley Medical Group, this one in the City, where they have been particularly busy recently because 'everyone's just had their bonuses'. Tammy, the nurse who sees me, is open about scarring and redness and pain and how much time I'll have to take off work. She explains that the Harley Group only recruits surgeons who are members of BAAPS. I haven't filled in my GP's name on the form and she makes a point of asking for it again (which neither of the others did), although when I say I don't want to give it she doesn't seem to mind.

This time, I am apparently in need of eyelid surgery, which Tammy calls blepharoplasty. (According to historian Sander L. Gilman, author of Making the Body Beautiful, this follows a common pattern: the lower the status of the specialism with other doctors, the more complex and 'scientific' its practitioners like to sound.) Although I haven't had to pay for this appointment, she says I need to discuss this blepharoplasty with a doctor, picks up the phone, organises it and requires payment there and then (although at £75, this is still cheaper than seeing Maurizio).

I leave feeling more depressed than ever and not just because I've discovered another thing wrong with my face, which needs to be fixed at a cost of £3,500. Feeling uncomfortable about technologies that promise to make us more attractive seems a little silly, but I am mistrustful of the version of the good life that seems to be proposed by plastic surgery.

American academic Joan Jacobs Brumberg has analysed the private diaries of adolescent girls born a century apart. In 1892, one of her diarists was writing: 'Resolved not to talk about myself or feelings. To think before speaking. To work seriously. To be restrained in conversation and action.' By 1982, typical girlish ambitions had shifted: 'I will try to make myself better in any way I possibly can. I will lose weight, get new lenses, already got new haircut, good make-up, new clothes and accessories.' We have moved away from an idea of character to one of personality and, specifically, of personality expressed largely through appearance.

By changing her appearance, Brumberg's twentieth-century diarist believes she can change her identity. This is the promise of cosmetic surgery, as philosopher Carl Elliott (and author of the best book on the subject, Better Than Well: American Medicine Meets the American Dream) explains although, to him, it is a flawed promise: 'The problem is not just that certain people's looks don't meet the standards of the culture, but also that the underlying set of social structures demand so much of self-presentation. In America, your social status is tied to your self-presentation, and if your self-presentation fails, then your status drops. If your status drops, then so does your self-respect. Without self-respect, you cannot be truly fulfilled. If you are not fulfilled, you are not having a truly meaningful life. This is the cruel logic of our particular moral system.'

Patients talk about cosmetic surgery in therapeutic language - 'I'm doing this for me'; 'I want to feel better about myself.' The therapeutic world-view assumes that human lives are projects that can be tweaked and reworked and adjusted to improve the inner experience. But this may be a dangerous path to start on, because if I can never be sure that my inner experience is as good as yours, let alone as Victoria Beckham's, then I will always be susceptible to suggestions that mine could be (expensively) improved.

And then life becomes a highly solipsistic experience: all me, me, me. Is that really what we want? 'It is tremendously exciting to see the world as an instrument for the achievement of our interests,' Carl Elliott observes, 'but it risks a sense that the world, by being bent to accommodate human designs, has been stripped of the very things that once gave it richness and meaning.'

It turns out that I'm lucky: I belong to a social group in which it is not yet expected that you'll spend thousands of pounds and start slashing your skin as soon as you hit 40. I told my most stylish friend about my adventures in cosmetic surgery and he said he'd be really appalled if I ever had anything done. 'It's not for people like you,' he said. Too Essex? I asked (I can say this, because I am from Essex). There had been a lot of women with dyed blonde hair and tans in those waiting rooms. 'Or Mayfair,' he said. 'One or the other.'

I have no faith that it won't come, though, even though my mother insists that the whole point of eyesight deteriorating with age is that you can't see yourself properly in the mirror.

The slashing might, I suppose, quite soon be overtaken by gene therapy: 'Destined to get forehead lines? Let's tweak a chromosome.' And that'll be another set of risks and another ethical can of worms.

Would you consider cosmetic surgery?

Dilys, 61, retired

'I'd be very reluctant to have anything around the face done. I'd be too afraid of disasters or complications. But anything below the neck is fair game - tummy tuck, arms, thighs.'

Dearbhla, 57, actress

'Absolutely not. Working in America, I found looking my age was a help, not a hindrance. For all the necessity of looking good in our profession, especially around the eyes, I would only consider it in an act of desperation.'

Mary-Anne, 43, social worker

'I wouldn't have it for vanity's sake because once you start you can't stop. On the other hand, maybe a tummy tuck. Or perhaps around the eyes...'

Kate, 33, PR executive

'No - I'm too terrified. I can't even have injections. I'm far too squeamish.'

Interviews by Michael Parker