Despite being shaken awake by almost every person I've ever shared a room with, I've been in denial about my snoring. Looking back, there were plenty of signals that it was a problem. My first girlfriend had to go to bed before me to fall asleep first, otherwise my snoring kept her awake. Many years later, when my family and I stayed in a farmhouse in the south of France, my children woke me in the middle of the night, hysterical because they were convinced a wild boar had got inside. Friends, sleeping in a small outbuilding separate from the main house, claimed they could hear me snoring, too. We joked about it and everyone said I should go to the doctor, but to me snoring seemed trivial compared with a real disease.

I believed this until I was commissioned to make art about sleep for the new Centre for Sleep at Royal Brompton Hospital. As research I read books on sleep, talked to the staff in the department and soon learned that, although they treat a range of sleep conditions that include narcolepsy, sleep walking and nightmares, by far the greater part of their work involves breathing problems during sleep, such as obstructive sleep apnoea. In fact, the Royal Brompton treats more than 7,000 people with the condition. To discern the size of a patient's problem, they do home sleep studies and for research purposes, they offered to carry out this study on me.

This involved taking home a kit and at bedtime dutifully attaching a snoring microphone, oxygen level and breath monitors, tapes to measure chest movements and a device that records how much you move during the night. I slept soundly, or so I thought, and returned the machine to the hospital the next morning, where Professor Anita Simonds, consultant in thoracic medicine, explained my results. "What is happening is that as you move from stage one sleep into deeper sleep, your body relaxes, including the muscles [that] hold open your throat. As your throat flaps close, your snoring worsens and eventually you take a big breath then … simply stop breathing.

"After a few seconds your oxygen levels drop and, when they reach around 70%, an emergency response is tripped in your brain, which wakes your body up. Not enough to become fully conscious, just to tighten the muscles so that you start breathing again. This happens many times a night. You wake thinking you've slept through, but feeling utterly exhausted." That's me exactly. I drag myself out of bed, shattered, have a shower and a cup of tea, then I'm just about ready to pull my clothes on. Simonds adds: "You've developed a coping strategy. That's how you manage to function."

It is thought that sleep apnoea affects up to 4% of middle-aged men and up to 2% of middle-aged women. Diagnosis tends to come from anxious husbands and wives who hear their partner struggling to breathe. Snoring alone isn't a sign of apnoea; the real signal is the frightening silence when snorers stop breathing. Obstructive sleep apnoea is associated with an increased risk of heart disease, stroke, and excessive tiredness during the day, and can be life threatening due to the cumulative adverse effect on heart and brain function leading to heart attack or heart rhythm irregularities. Mostly though, it affects concentration, memory, family life and performance at work. In severe cases, exhaustion causes sufferers to fall asleep: about 20% of road traffic accidents are thought to be due to drivers falling asleep at the wheel. Not all have sleep apnoea but the risk of traffic accidents rises up to seven-fold among those who do. Luckily, when I fall asleep at the drawing board, the worst I can do is upset a bottle of ink.

Treatments include weight loss for the overweight and a dental splint, worn over the teeth at night to push the lower jaw forward and open the airway. But continuous positive airway pressure (CPAP) therapy is the treatment of choice for moderate and severe cases. This provides a flow of pressurised air through a face mask that helps to hold the airways open so that the apnoea sufferer can breathe.

I set it up beside the bed, fit the mask over my face, tighten the velcro straps and set the machine running. A timer starts the air pressure at a low level then slowly ramps it up so that it reaches full strength after you've fallen asleep. Despite the strangeness of the blast of air, I close my eyes and fall asleep in moments. Then I am awake again. Somehow I don't get on with the mask at all. It is uncomfortable and every time I move, pressurised air leaks out and wakes me.

Jayne Bullock, a long-time patient in the sleep department, says you have to persevere. "I've been using it for 12 years and it took a long time to get used to, but now I can sleep right through. It's a little bit like wearing glasses. Some people find it's not a problem at all, others find it really intrusive. It's also a psychological thing: you've got to force yourself to, because you know if you use it you're going to feel much better."

A friend told me that when her father got a CPAP machine his life improved dramatically. "He felt 10 years younger; full of energy," she says.

Perhaps the aches, pains and tiredness, which I always assumed to be the inevitable consequence of growing old, are actually the result of sleep apnoea. Maybe when I get the mask working right, the bags under my eyes will melt away and I'll look younger too?

Pass me that machine.