While awake, breathing is usually easy and quiet. When asleep, the upper airway, between mouth and vocal cords, narrows as the body relaxes. It can also be affected by large tonsils. Smooth airflow can then be replaced by turbulent airflow which may cause vibration of the tongue, palate or throat. This results is the noise of snoring. This is very common. Although not usually life-threatening, it can be anti-social for loved ones, family and friends. The likelihood of snoring is increased by being overweight, smoking, drinking too much alcohol and sleeping in the back position.
Sleep apnoea means no breathing during sleep. Obstructive sleep apnoea (OSA) is the commonest type. During deep sleep, the upper airway collapses completely meaning that breathing stops which leads to a fall in oxygen levels. The resulting survival stress response leads to lighter sleep when breathing restarts. Deep refreshing sleep then follows as the body relaxes once again. However this sequence can occur multiple times through the night which disturbs normal sleep resulting in non-refreshing sleep. Morning headaches may be reported. Daytime sleepiness, poor concentration and memory problems may ensue. Because sleep is lighter, OSA frequently leads to multiple awakenings through the night to pass urine. Long term, OSA increases the risk of high blood pressure, heart disease, abnormal heart rhythms, stroke, diabetes, depressions and erectile dysfunction. A general anaesthetic can be riskier if untreated OSA is present.
Insomnia is common. It can present as difficulty in initiating sleep or maintaining sleep. It may be caused by another underlying sleep disorder such as sleep apnoea. A stressful life event can precipitate insomnia which sometimes persists for a long time.