Carlo Zappulo once snored so loudly it almost wrecked his marriage.

For more than six mind-numbing years his long-suffering wife, Carmen, was regularly forced to sleep in the spare room to get a decent night's rest.

If Carlo wasn't snoring he would suddenly stop breathing, sending his oxygen-starved body into convulsions which terrified both of them.

It was a situation which slowly took its toll on both their tempers and their relationship.

Carlo, a 33-year-old locksmith, said: "I was a very bad snorer and it affected Carmen a lot. She couldn't sleep because of me. I felt really sorry for her.

"I was also very moody, tired and stressed. I was taking a lot of things out on her but she gave me a lot of support."

Carmen, 32, a credit control supervisor, said: "It was a nightmare. Neither of us slept. It came between us and put a huge strain on everyday life. We were constantly shattered."

At work, Carlo would be talking to a friend or reading the newspaper when he would suddenly nod off.

He lost count of the number of times he almost fell asleep at the wheel of his car.

Carlo and Carmen, of Cortis Avenue, Worthing, said they attended at least a dozen hospital appointments in a desperate bid to find out what was wrong.

Carmen said: "The doctors thought it was a nasal problem but it was obvious there was something more to it."

The couple were at their wits' end when a GP finally referred them to a specialist breathing unit at the King Edward VII Hospital in Midhurst.

Staff there immediately identified a condition called sleep apnoea which can have devastating consequences if left untreated.

The condition increases the natural narrowing of the throat during sleep to a point where airways become blocked and the sufferer momentarily stops breathing.

Carlo was given a mask to regulate the flow of oxygen into his lungs during sleep.

A year later, Carlo and Carmen have been sleeping like proverbial babies, which has rejuvenated their 11-year-old marriage.

Carlo said: "I will have to wear the mask at night for the rest of my life but now I feel 80 per cent better.

"I left it off once to see what the difference would be and Carmen said I went back to how I was before, only worse."

Carmen said she was delighted with the improvements and did not mind him wearing the mask at night because "at the end of the day it is going to save his life".

In the past six months Worthing Hospital has treated more than 250 people for sleep apnoea.

Dr Kate Steele, a consultant respiratory physician, said: "Sleep apnoea has a big impact on quality of life. A lot of people have been like this for years and are chronically tired."

Snoring affects 45 per cent of the population from time to time and an estimated 25 per cent of people are habitual snorers.

Sleep apnoea is characterised by periods when breathing stops during sleep.

These interruptions, which can last ten seconds or longer, occur when the muscles in the soft palate, uvula, tongue and tonsils relax during sleep. In sleep apnoea the airway narrows so much that it closes.

This cuts off the flow of oxygen into the body and reduces the elimination of carbon dioxide (CO2) from the blood. The brain detects this rise in CO2 and briefly wakes the sleeper in order to reopen the airways.

Sleep apnoea can increase the risk of heart problems because it deprives the sufferer of adequate levels of oxygen, making the heart work harder than normal.

It is thought to affect almost one in 20 men, with three in every 1,000 severely afflicted.

Sometimes a sufferer wakes up every 30 seconds, causing severe daytime tiredness.

Official figures show sleep apnoea sufferers are seven times more likely to be involved in a car crash.