To the outpatients milling around the reception area of King's College Hospital on a rain-sodden Tuesday morning, Matthew must seem a picture of health. Tall, thick-set and slightly tanned, there is nothing in the 29-year-old's appearance to suggest infirmity.

But for Matthew, this hospital visit is the latest in a long line of tests, examinations and treatments that have done little to alleviate the symptoms he has suffered for the last five years.

In August 1989, Matthew was diagnosed with chronic prostatitis, an infection or inflammation of the prostate gland, sometimes equated with cystitis in women. Lying beneath the bladder and surrounding the urinary passage, the prostate is a male reproductive and sexual gland that produces fluids to nourish and transport sperm.

Although prostate problems are associated with middle and old age, prostatitis is increasingly prevalent amongst men in their twenties and thirties. And for first- time sufferers, the onset of symptoms can come as a shock.

'I started to get a burning sensation when I peed,' Matthew says. 'I wasn't too worried at first. I assumed it was just a urine infection. But then I developed constant aching in what I now realise was the prostate. That's when I really started to think there was something wrong. I panicked. I couldn't concentrate on anything but this problem.'

Assuming it was a venereal disease, Matthew's GP referred him to an STD clinic. But despite taking urine samples and swabs from inside the penis, no evidence of infection was found.

'All the tests drew a blank, but they diagnosed me with non-specific urethritis. Which is another way of saying 'we haven't got a clue'. They gave me a course of antibiotics and told me to come back in two weeks. I thought the tablets would work, but they didn't make the slightest difference.'

On his second visit to the clinic, the doctor suggested it could be a prostate infection and referred him to a urologist. As well as his initial symptoms, Matthew was now having problems in his sex life, experiencing some pain on ejaculation. By the time of his urologist's appointment, he was 'worried sick'.

Examination of the prostate gland can be a painful experience. The urologist inserts a gloved finger into the rectum and presses on the prostate to express fluid out through the urethra. The fluid is then examined for signs of infection. This process is called a prostatic massage.

'I think it was the word 'massage' that threw me. At worst, I thought it would be mildly uncomfortable. He examined the righthand side of the prostate and that wasn't too bad. But when he pressed on the left side, I nearly shot through the ceiling. It was agony.'

Prostatitis sufferers can experience a whole range of symptoms, from pain and discomfort in the penis, testicles and prostate to recurrent cystitis. And most disturbingly for young men, painful and premature ejaculation.

In some cases, urologists are able to identify infection in prostatic fluid and treat it successfully with antibiotics. But in most cases, despite evidence of inflammation, no infection can be found. This common form of prostatitis leaves sufferers like Matthew exasperated and urologists perplexed. 'Prostatitis is a bit of a nightmare condition in terms of being able to say what it is, what causes it and what the management is,' says Neil O'Donahue, a consultant urologist at the Middlesex Hospital. 'Probably only a minority are due to infection. And the problem is, what causes the others?'

The spongey nature of the prostate only adds to the urologists' problems when prescribing treatment. Infective bacteria may be trapped in the gland because swelling has blocked off the usual channels. And only a few antibiotics can penetrate the prostate.

'Most ordinary, penicillin-derived antibiotics are ineffective,' says Mr O'Donahue. 'For that reason people use the newer antibiotics like ciprofloxacin, which has a broad spectrum of activity against many bacteria. But that doesn't necessarily mean it will relieve the symptoms.'

None of which is exactly comforting for sufferers. But, worrying though the symptoms are, the condition is not a serious threat to patients' health. There is no evidence to suggest that sufferers of prostatitis are any more susceptible to prostate cancer than non-sufferers. Neither is it believed to be sexually transmittable. And although the condition tends to recur it can remit for months or years at a time.

Matthew believes that the lack of information about prostatitis added considerably to his sense of isolation when he first developed symptoms. A health advice leaflet, he says, would have helped to minimise his distress.

It is a situation that Patrick O'Reilly, a consultant urologist, is anxious to see change. As Honorary Secretary of the British Association of Urological Surgeons, he is keen to raise awareness of prostatitis to ensure that sufferers like Matthew are informed about their condition.

'Prostatitis is extremely common in young men. And it's a real problem. Women talk about cystitis all the time. Information is readily available in surgeries and clinics. And women's magazines give it a very high profile. But many men who get prostatitis haven't got a clue it exists and it's not a problem men tend to talk about. They're worried but they're also embarrassed so it takes longer for them to go and see a doctor about it,' he says.

Mr O'Reilly is producing information leaflets for the prostatitis patients who attend his clinic and is keen to see a heightened awareness of the condition among GPs. As yet, no statistics exist as no studies have been conducted on the prevalence of the condition in young men.

Five years on, Matthew is still hoping to find permanent relief and next month he will have surgery. Under local anaeshetic, a tiny object known as a prostatic microwave will be inserted into his penis and down his urethra. It will warm the prostate to 40C, speeding up the blood flow with the intention of helping his body's immune system to kill any bacteria within the gland.

It is a humiliating experience for the patient, but urologists are encouraged by the results of this new technique. 'When you've suffered as long as I have,' says Matthew, 'you'll do anything to co-operate. Besides, I've grown so used to having my private parts prodded and poked by doctors, I think I'm immune to embarrassment.'

'P For Prostate', by Sarah Brewer, is available from Primart, PO Box 164, Yately, Camberley, Surrey GU17 7RX (0252 861234). Prostate Help Association, Langworth, Lincoln LN3 5DF; send sae for information.