The sleep Apnea problem has been gaining more publicity. Obstructive sleep apnea (OSA) is a condition in which breathing stops during sleep for more than 10 seconds. A person with sleep apnea faces frequent episodes, mostly 400 to 500 per night, in which a person stops breathing.
Ways sleep apnea can be harmful to health
Obesity is the most important predictor of sleep apnea. It has long been known that obesity plays a key role in the development of sleep apnea. It is estimated that 60 to 90 percent of patients with sleep apnea are obese (defined as BMI > 28 kg / m2) and that the 28 kg / m2 BMI has a sensitivity of 93 percent and a sleep apnea specificity of 74 percent. 
- Cardiovascular disease
Sleep apnea may harm your heart’s health. Sleep apnea has been associated with heart failure and high blood pressure, which increases the strain on your heart. Mechanisms involved in cardiovascular disease include sustained sympathetic activation, changes in intrathoracic pressure, and oxidative stress. If you have apnea, you are more likely to have abnormal heart rhythms, such as atrial fibrillation, which may increase your risk of stroke. 
- Metabolic syndrome
A direct link has been established between metabolic syndrome and sleep apnea. Recent preliminary evidence suggests that metabolic syndrome may be more prevalent in patients with obstructive sleep apnea than those without OSA. Clinical data show that 60 percent of patients with sleep apnea had metabolic syndrome compared to 40 percent of patients without sleep apnea.
- Respiratory disorder
Sleep apnea causes breathing problems, causing you to stop breathing while you sleep. Sleep apnea worsens the symptoms of asthma and chronic obstructive pulmonary disease (COPD).
- Nervous system disorder
Sleep apnea can affect your brain. Sleep apnea has been associated with some cognitive disorders such as decreased concentration, poor memory, attention, and impaired motor skills. Sleep apnea also limits the amount of oxygen that goes to your brain, which can lead to morning headaches. Sleep apnea can also cause neurological symptoms such as numbness and tingling.
Studies have shown that OSA is associated with insulin resistance, glucose intolerance, and type 2 diabetes, regardless of obesity. Evidence from animal and human models that OSA mimics provide potential mechanisms for how OSA can alter glucose metabolism. Up to 83 percent of patients with type 2 diabetes suffer from OSA, and increased OSA severity is associated with worsening glucose control. 
Sleep apnea may increase hypertension. According to research, approximately 40 percent of patients with sleep apnea suffer from hypertension, while 30 percent of hypertensive patients have occult sleep apnea. Evidence shows that systolic and diastolic blood pressure and hypertension prevalence increased significantly with sleep apnea severity.
- Risk of Glaucoma
Sleep apnea is one of the risk factors for glaucoma that causes irreversible visual field (VF) damage. Rising intraocular pressure (IOP) is one of the major risk factors for glaucoma. It causes mechanical damage to the ONH and the inner retinal layers, resulting in the VF’s progressive, irreversible functional loss. 
OSA may make you excessively sleepy and cause you to fall asleep when you are driving. The risk of fatal car accidents is much higher.
Repeated sleep apnea-related awakenings make regular, restorative sleep impossible, making severe daytime sleepiness, fatigue, and irritability likely.
- Lisa Morrone, Ron Eaker: Overcoming Overeating: It’s Not What You Eat, it’s What’s Eating you. Harvest House Publishers, 2009
- Girardin Jean-Louis, Ferdinand Zizi, Clinton D. Brown: Obstructive Sleep Apnea and Cardiovascular Disease: Role of the Metabolic Syndrome and Its Components 2008 Jun 15; 4(3): 261–272. Available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2546461/
- Sushmita Pamidi, Esra Tasali: Obstructive Sleep Apnea and Type 2 Diabetes: Is There a Link? Published online 2012 Aug 13. DOI: 10.3389/fneur.2012.00126
- Aditya Chaitanya, Vijaya H. Pai: Glaucoma and its association with obstructive sleep apnea: A narrative review 2016 Sep-Dec; 9(3): 125–134. DOI: 10.4103/0974-620X.192261