Disturbed and interrupted sleep can cause a wide variety of problems, from the minor to the very serious. Disturbed sleep can make a person drowsy during the day. Fatigue is the main complaint expressed by apnea sufferers.  Untreated sleep apnea is also been linked to these conditions:

Accidents

Increased Mortality

Cardiovascular Disease

Inability to Lose Weight

Diabetes

Poor Quality of Life

Hypertension

Stroke

Increased Healthcare Costs

Weight Gain, Slow Metabolism