In late May 1991, when I tested HIV-positive aged 24, I never dared to hope that I would be alive 14 years later. At the first appointment with my consultant, I learned that approximately half of my immune system, judged by the number of CD4 cells (my count was 400, compared to the normal range of 800 - 1,200), had already been wiped out by HIV. I was told that within five years I could expect to start developing the serious, Aids-defining infections that affect HIV-positive people as their immune system weakens, and that within about a decade I'd be dead. I was offered the chance to take the only available anti-HIV drug then available, AZT, but declined, preferring to save it for later.

Thankfully, it hasn't quite worked out like that. True enough, my immune system did weaken over the years, and by summer 1994 I was told that I'd progressed to Aids after I was diagnosed with tuberculosis. I reconciled myself to the idea that I would be dead by my mid-30s. But then something extraordinary happened.

The advent of effective antiretroviral drugs has transformed the life, and the life expectancy, of people such as me and Chris Smith, the former cabinet minister who admitted at the weekend that he too was diagnosed with HIV, in the late 1980s. I've now been taking a combination of anti-HIV drugs, more properly known as highly active antiretroviral therapy, or "Haart" for short, since early 1998. My CD4 cell count has increased five-fold, and the amount of HIV in my blood, my viral load, has fallen to undetectable levels and stayed there.

It would be easy to conclude, for me at least, that antiretroviral therapy has been a stunning success. Indeed, my HIV consultant has told me that, aside from my HIV antibody count, my immune system is now so healthy that he would never guess that I had HIV. Meanwhile, I have been in more or less continual full-time employment since I started Haart and I have run three full marathons and dozens of half-marathons since 2000, never finishing outside the top 5%. Being honest, I no longer think that I will die prematurely of Aids, and believe the predictions of many leading HIV doctors that with appropriate treatment a person with HIV can expect to live a more or less normal life-span.

But it would be a mistake to believe that the advent of drugs that can so transform the lives of people such as me, and of a general climate in which a leading politician can announce his positive status to a broadly favourable reception, means that life for HIV-positive people is now rosy. I have no doubts about the seriousness of HIV, and the extent to which it will impact on every aspect of my life. Although antiretroviral therapy can successfully control the effects of HIV, none of the currently available anti-HIV drugs, or even those in the very earliest stage of development, will provide a cure. Around 400 people are still dying every year because of HIV in this country.

My health, therefore, is still a real cause of anxiety - specifically that I will develop resistance to one or more of my anti-HIV drugs. It is easy for HIV to become cross-resistance to drugs of the same type, so if you develop resistance to one drug, you potentially lose the option of using a similar one in the future.

To minimise this risk, it is essential to take 95% of your drugs at the right time and in the right way, every day for the rest of your life. When treatment with combinations of antiretrovirals first became available in 1996-97, this meant having to take as many as five separate doses a day, each involving a handful of pills. Simpler treatments have since become available, but my current combination involves five pills, twice a day with food. Although I do prioritise my pill-taking, I am only human, and occasionally miss a dose.

Side-effects also loom large. My first year of anti-HIV treatment was, quite simply, a misery. I had such severe diarrhoea that it felt like a tap had been turned on in my bowels. One drug (which, thankfully, I stopped after a couple of months) damaged the nerves in my feet and lower legs, a condition called peripheral neuropathy, and caused pain so severe that I had to take a morphine-based painkiller. Although it is five years since I stopped taking this drug, I still have numbness in my feet, and waddle, rather than walk, if I'm not wearing shoes.

Despite my running, the drugs pose a long-term risk to my cardiovascular health. Anti-HIV drugs, particularly some protease inhibitors (one of which I take) can increase levels of blood fats and sugars, and have caused increased rates of heart disease and diabetes in some people taking them. A long-term illness such as HIV can also cause inflammation which can damage the heart. Occasional high cholesterol, an irregular heart beat, and a family history of heart disease has meant that I am one of the growing number of HIV patients who has needed to see a cardiologist.

Thankfully, I've been spared the disfiguring changes in body-shape (called lipodsystrophy) that some anti-HIV drugs cause. Symptoms can include the stripping of fat from the limbs and buttocks, the accumulation of fat around the internal organs, fat gain at the back of the neck and fat loss from the face. This syndrome of side-effects can be very stigmatising, a real indicator that a person has HIV and is taking medication. Treatment options are limited, and for many, cosmetic surgery seems to be the only option. A close friend who has had several courses of treatment to temporarily correct fat loss from his face summed up his feelings thus: "It's the ultimate irony - you're spared dying of Aids only to look like you are."

The illness has also had a huge impact on my mental health: I feel worn down by my 14 years with HIV. This has resulted in several episodes of major depression, each of which has been at least as debilitating as any of the physical illnesses I've experienced. I know I'm not alone in this. Although there are fewer suicides among people with HIV than in the past, the rate of depression has gone up since effective anti-HIV treatment became available. For some people the drugs themselves appear to be the reason. Then there are the emerging medical concerns, such as the excess rates of certain rare cancers that are now being seen in people with HIV.

Nor are my uncertainties simply medical. I lack any real financial security; due to illness my employment history is chequered. I do not and don't expect, I will ever own my own home, and although I'm now paying into a pension plan I worry that it is too little and too late. Chronic poverty, like chronic disease, may well be awaiting me in the old age that HIV treatment now seems to be offering me.

However, like Smith, I no longer want to hide the fact I have HIV. I ignore the inquiring looks from fellow diners as I take my handful of pills; if somebody asks how I got my central London housing association flat, I truthfully tell them, "It's because I've got Aids." But openness about HIV can still have unwanted consequences. I had to move from a previous flat in south-east London due to harassment after the locals found out about my status. Having HIV has also limited my ability to travel. The US routinely bars entry to people with HIV, and I'm not prepared to obtain the special entry visa required that will inform immigration officers around the world that the US regards me as undesirable.

I've never told my parents I have HIV (I hope my dad isn't tempted by today's Guardian rather than his usual Mirror). I tell myself that it is to spare them having to worry about me, but sometimes I wonder if there is a part of me that is ashamed of having HIV. Perhaps, after 14 years, it wouldn't be so bad if they found out through this article. I am also very aware that I have had excellent treatment for my HIV while my chronically ill parents, who worked a lifetime to fund the NHS, have to wait months for appointments and even longer for treatment.

I also try to maintain a sense of perspective. I'm thankful that my partner no longer has to worry about the prospect of my premature death, and I no longer want or expect people to make the same allowances for me that they did. The problems I now face are more generic - lots of people live with chronic and controllable illness; many people live in pain; financial insecurity is a fact of life for millions in the UK today.

The anti-gay legislation of the Thatcher government was a key factor in the development of my identity as a young gay man in the late 80s and early 90s. In 1996, effective anti-HIV treatment became available; the following year came the Labour government (of which Smith was part), which equalised the age of consent, repealed Section 28, gave gay people the right to serve in the military, employment rights, and most recently, civil partnerships. Smith's admission in 1984 that he was gay and in 2005 that he has HIV shows how the clouds that hung over my early 20s have to a large extent dispersed.

But that is not to say that HIV is no longer a serious health concern for gay men. In 2004 more gay men than ever were diagnosed HIV-positive in the UK. There are few accurate portrayals of HIV in the UK media, and polls conducted by the Terrence Higgins Trust show a shocking level of fear and ignorance about HIV.

Thanks to anti-HIV medication I'm alive when I expected to be dead. But it is essential to acknowledge that life with antiretrovirals has brought its own set of problems. The first step to dealing with them is to admit that they exist.

HIV: To tell or not to tell?

Pete (not his real name), 37, discovered that he was HIV positive in 2001. He is a writer

Telling people you're HIV positive is a bit like coming out all over again. It's only now that I'm starting to feel comfortable with it and have just recently told three very close friends. Other than that, nobody else knows. The problem with telling people is that you lose control a little, and there is always the danger that you become defined by your illness. It was only when I started becoming sexually active again that I decided to tell anybody. It seemed perverse and somehow unbalanced that I was telling these complete strangers on a one-night stand, yet kept it a secret from my best friends.

Angie, 37, works for Positively Women, a charity which works with women and families affected by HIV

I was 26 when I was first diagnosed in 1993. I didn't tell anyone for three years. I felt like I was the only woman in London with it. The day I got my test I was offered a job with a health authority in London and I took it, thinking, "Oh well, I might as well work while I'm waiting to die." That's what I thought lay in store for me. I didn't disclose my condition to my colleagues the whole time I worked there. It was only when a friend disclosed to me that she was HIV positive that I admitted that I was too. But even now I don't tell many people outside of work.

Andy, 37, works in IT. He was diagnosed in November last year

When I found out, I told virtually everyone - I'd phoned two friends in California before I'd even got off the bus from the clinic. I haven't told my parents, just because they're in their 60s and deeply religious. I really don't want to worry them and given that I'm not actually ill, it doesn't affect my relationship with them. Now the problem with having told everyone my status, is that I have to keep everyone informed. I think if I were to go through it again, I'd probably not tell quite so many people, and certainly not quite so quickly."

Andrew Sullivan, 41, is the Washington columnist for the Sunday Times, a senior editor at the New Republic and blogs at andrewsullivan.com

I was diagnosed in 1993. I immediately told my boss, and friends, but kept it from my family. My problem was that I was an openly gay man in a very public position. I decided that the news would completely dominate my career and make it impossible to do the work I was doing. Three years later, when I had a better grip on the situation, and after I had nursed my best friend to death, I decided to quit my job and in the final editorial meeting, told my colleagues that I had HIV. It kind of eclipsed all the usual media gossip about an editor leaving after internal clashes at a magazine. Now, amazingly, almost no one notices. Since the medical revolution that began in 1996, Aids has become more and more like, say, cancer or hepatitis. A tough diagnosis which you can live with. I've been off meds now for three years and my numbers are stable. I expected to be dead by now. Yes, that's a head trip. But I'm too alive to worry about it too much.

Andre Davies, 29, works in marketing. He was diagnosed in 1994

I found out that I was HIV positive when I was in hospital for something else in Jamaica, where I am from, and had a routine test. I was only 17. I didn't tell anyone; I knew if the gay community found out I would be ostracised. When my partner died later that year rumours started to circulate that he had HIV, and I started getting a lot of hassle. I kept my head down, went out as little as possible, finished my studies and left the country as soon as I could. My parents still don't know now - they wouldn't understand, there's so much misinformation in Jamaica. I tell my employers, just because then it's easier to get time off if I am ill. I certainly don't tell colleagues, though. I guess I fear the rejection. But not telling doesn't mean I put anyone else at risk. I tell long-term partners, but otherwise I just practice safe sex.
Interviews by Helen Pidd

· Living with HIV by Michael Carter is available free of charge from NAM on 020-7840 0050, or email info@nam.org.uk