Lack of Oxygen to the cells in your body during sleep apnea events has many dangerous effects. The most common EIGHT consequences are listed in an American Academy of Sleep Medicine article: I have printed them here for you.

1. High blood pressure
Studies have shown that OSA can cause high blood pressure, also known as “hypertension.” The amount of increase in blood pressure is related to the severity of OSA; more severe OSA produces greater increases in blood pressure. Elevations in blood pressure even can occur in children who have OSA. 

2. Heart disease
Untreated OSA is a risk factor for heart disease, which is the leading cause of death in the U.S. as of 2005. OSA increases your risk for an irregular heartbeat, coronary artery disease, heart attack and congestive heart failure. A 2006 study in the Journal of the American College of Cardiology found that OSA even affects the shape of your heart. Results show that the hearts of people with OSA are enlarged on one side, have thickened walls and a reduced pump function.

3. Stroke
OSA increases your risk for stroke, the third leading cause of death in the U.S. as of 2005. A stroke is a “brain attack” that occurs when blood flow to the brain is interrupted. It can result from either a blood clot that blocks an artery or from a broken blood vessel.

4. Brain damage
A study in the journal Sleep in 2008 provided visual evidence of brain damage that occurs in people with OSA. The damage affects brain structures that help control functions such as memory, mood and blood pressure.

5. Depression
Research shows that depression is common in people with OSA. Even mild OSA gives you a much greater risk of depression. This risk for depression increases with the severity of OSA.   

6. Diabetes
OSA is associated with impaired glucose tolerance and insulin resistance. Type 2 diabetes, a leading cause of death in the U.S. , occurs when the body fails to use insulin effectively. Research suggests that OSA can contribute to the onset of diabetes.

7. Obesity
Obesity is a key risk factor for OSA. But there is increasing evidence that OSA also may promote weight gain. OSA can fragment sleep, reducing daytime energy and physical activity. It also can disrupt metabolism. OSA may alter the levels of hormones that regulate your appetite, which may lead you to eat more.

8. Mortality
Two studies in the journal Sleep in 2008 show that people with sleep apnea have a much higher risk of death than people without sleep apnea. The risk is greater for people whose sleep apnea is more severe. The risk of death also increases when sleep apnea is untreated.

As a member of the American Academy of Sleep Medicine, I receive the Journal SLEEP, and have used its articles in my hospital lectures and in my class presentations at Michigan State School of Osteopathic Medicine
There is hope for people who have OSA; it can be treated with a high rate of success.   A growing body of research shows that treating OSA with either continuous positive airway pressure (CPAP) or oral appliance therapy can reduce many of these eight health risks.