SNORING falls into that small category of medical conditions, along with haemorrhoids and gout, which sounds comical until you or someone you live with falls victim to it.

The British Lung Foundation has recently looked under the covers to survey people in the north of England and found a staggering 40 per cent of couples sleep in separate beds because of their partner’s loud snoring.

For many, snoring could be just be caused by sleeping in an awkward position, especially on your back, or perhaps after too much alcohol. But for some it can be a symptom of a far more serious condition, one which can completely disrupt a sufferer’s life Snoring is one of the common symptoms of the sleep disorder obstructive sleep apnoea (OSA), which is caused when the upper airways become repeatedly blocked during sleep. This sleep disruption leaves patients struggling to stay awake during the day.

According to the BLF, it is estimated that four per cent of middle-aged men and two per cent of middle-aged women have OSA, but experts believe the size of the problem is far larger.

The findings have prompted the BLF to launch an investigation to find out why so many people go undiagnosed.

The consequences of the condition could be fatal, with an estimated 20 per cent of all accidents on motorways caused by sleepiness.

We spoke to Margaret Dawson, 61, from York, who cared for her husband before he died of mesothelioma ten years ago. She did not realise she was suffering from sleep apnoea when she developed it two years after losing her husband.

“I was breathless and I was falling asleep and I wasn’t eating properly,” she said. “I was retaining a lot of water and I doubled in size. I couldn’t walk more than nine or ten yards without stopping.

“I couldn’t get from my front door to my garden gate.

“It was my daughters who picked up; I didn’t realize what was happening to me.

“I would fall asleep for ten minutes. I could be in the middle of a conversation and I would just nod off then wake up and carry on the conversation.”

Margaret also snored very loudly, which was noticed by her neighbours, especially in the summer.

Her worried family had feared she had “given up on life” after her husband’s death, but she was actually suffering from such severe sleep apnoea that she was eventually admitted to hospital for a month and a half.

She said: “One of my daughters kept taking me to the doctors and he just kept saying “there’s nothing wrong”.”

“My daughters eventually demanded that I get a home visit from a GP. He came and rang the hospital and I was admitted to Accident and Emergency.

“I was so bad my heart was actually stopping and I would gasp for breath and that would jolt me awake. That was going on quite a few times each night. When I woke up on a morning, it felt like I had never been to sleep.”

Due to the excessive daytime sleepiness caused by sleep apnoea, Margaret didn’t drive for nine or ten months after diagnosis, of her own accord, but had her driving licence revoked by the DVLA anyway. Her licence is now reviewed every three years.

Margaret was given something called a continuous positive airway pressure (CPAP), a mask which delivers oxygen as she sleeps and said she is now a different person.

Bev Wears, support and development manager for the British Lung Foundation North said: “We all brush off snoring as an annoying habit but we don't really consider that it could be detrimental to our health.

“Given that extremely loud snoring is one of the main symptoms of obstructive sleep apnoea (OSA), we are urging anyone who is concerned to go to www.lunguk.org/sleep to find out if they are at risk.”

According to the NHS, the lack of oxygen causes the person to come out of deep sleep and into a lighter state of sleep, or a brief period of wakefulness, in order to restore normal breathing.

However, after falling back into deep sleep, further episodes of apnoea and hypopnoea can occur. Such events may occur more than once a minute throughout the night.

The repeated interruptions to sleep caused by OSA can make the person feel very tired during the day. A person with OSA will usually have no memory of breathlessness, so they are often unaware that they are not getting a proper night's sleep.