People who have woken frequently during the night as a result of sleep apnoea, even without realising it, tend to feel sleepy the next day. The choking noises and the movements they make are also likely to cause serious disturbance to their partners.
Sleepiness and lack of concentration during the day can be hazards at work, for example when operating machinery or driving. Note that there are regulations from some Departments of Transport about driving if you have sleep apnoea.
There is some evidence that sleep apnoea may be linked to high blood pressure (hypertension), strokes and heart attacks.
Ask your doctor's advice about carrying a medical alert card. If you have serious sleep apnoea and you become unconscious (for example following an accident), you might need to be put on CPAP treatment to keep you breathing steadily.
Information source: NHS Direct Online Health Encyclopedia, 2005