My dad suffers from apnoea. He also has a realllly bad snoring problem and I think that the two are usually found together. It is probably a stress thing as others have suggested. I've had something similar at times. Its almost like you wake up with a big sigh.
On Apnoea;
"People who suffer from Obstructive Sleep Apnoea (OSA) slow or stop breathing for short periods while sleeping. This can happen many times during the night. It results in poor sleep with excessive sleepiness during the day. Because these events occur during sleep, a person suffering from OSA is often the last one to know what is happening.
In deep sleep, the muscles of the throat relax. Normally this doesn't cause any problems with breathing. In OSA, however, complete relaxation of the throat muscles causes blockage of the upper airway at the back of the tongue. Normal breathing then slows or stops completely. Such an episode is called an apnoea. During an apnoea, people with OSA make constant efforts to breathe against their blocked airway until the blood oxygen level begins to fall. The brain then needs to arouse the person from deep relaxed sleep so that the muscle tone returns, the upper airway then opens and breathing begins again. Unfortunately, when a person with OSA falls back into deep sleep, the muscles again relax and the cycle repeats itself again and again overnight.
In OSA, the apnoeas can last for 10 or more seconds and the cycle of apnoeas and broken sleep is repeated hundreds of times per night in severe cases. Most sufferers are unaware of their disrupted sleep but awaken unrefreshed, feeling tired and in need of further refreshing sleep.
Who gets OSA?
Whilst OSA is more common in overweight middle-aged males who snore, it can also affect females, although female hormones and a difference in throat structures may protect women until the menopause. Narrowing of the back of the throat and the upper airway can also contribute to the risk of getting OSA, even in people who are not overweight or middle-aged. In such people, a blocked nose, a small jaw, enlarged tongue, big tonsils, and uvula help to block the upper airway in deep sleep, making OSA more likely to occur. Several of these problems can be present in any person at the same time.
The use of alcohol, sleeping tablets and tranquillisers prior to sleep help to relax the upper airway muscles and make OSA worse. Alcohol can also reduce the brain's response to an apnoea which in turn leads to longer and more severe apnoeas in people who would otherwise only have mild OSA and who would otherwise only snore.
Most people with OSA snore loudly and breathing during sleep may be laboured and noisy. Sleeping partners may report multiple apnoeas lasting up to 90 seconds which often end in deep gasping and loud snorting. Sufferers may report waking for short periods after struggling for breath. Symptoms are often worse when lying on the back in deepest sleep."
