Topic Overview

Sleep apnea can cause you to stop breathing during sleep. When you stop breathing, the oxygen levels in your blood go down and carbon dioxide levels go up. This makes your heart and blood vessels work harder and can affect your heart rate and nervous system. This can lead to complications over time, such as:

  • Low blood oxygen levels during sleep. These low levels as well as other factors such as fragmented sleep may lead to high blood pressure in the lungs (pulmonary hypertension) and in the rest of the body (hypertension).footnote 1 Nearly 50% of people who have sleep apnea have high blood pressure.footnote 2
  • Heart failure. Changes in the body caused by sleep apnea increase the risk of heart failure.footnote 3
  • Irregular heart rhythms, such as atrial fibrillation.footnote 4
  • Coronary artery disease (CAD).
  • A greater-than-normal number of red blood cells, which may cause the blood to thicken.
  • Death caused by blood vessel disease that affects the brain or heart (stroke or heart attack).footnote 4
  • Failure to resume breathing (respiratory failure) and sudden death, especially in the early morning (very rare).

Sleep apnea can cause some of these conditions to progress more quickly and be more difficult to treat. Treating sleep apnea may help make some of these conditions less severe.

People with sleep apnea also may be more likely to get in a car crash due to sleepiness while driving.footnote 5

Related Information



  1. Wolf J, et al. (2007). Obstructive sleep apnea: An update on mechanisms and cardiovascular consequences. Nutrition, Metabolism and Cardiovascular Diseases, 17(3): 233-240.
  2. Guilleminault C, Abad VC (2004). Obstructive sleep apnea syndromes. Medical Clinics of North America, 88(3): 611-630.
  3. Kasai T, Bradley TD (2011). Obstructive sleep apnea and heart failure. Pathophysiologic and therapeutic implications. Journal of the American College of Cardiology, 57(2): 119-127.
  4. Pien GW, Pack AI (2010). Sleep-disordered breathing. In RJ Mason et al., eds., Murray and Nadel's Textbook of Respiratory Medicine, 5th ed., vol. 2, pp. 1881-1913. Philadelphia: Saunders Elsevier.
  5. George CFP (2004). Sleep 5: Driving and automobile crashes in patients with obstructive sleep apnoea/hypopnoea syndrome. Thorax, 59(9): 804-807.


ByHealthwise Staff
Primary Medical Reviewer Anne C. Poinier, MD - Internal Medicine
Donald Sproule, MDCM, CCFP - Family Medicine
Adam Husney, MD - Family Medicine
Specialist Medical Reviewer Mark A. Rasmus, MD - Pulmonology, Critical Care Medicine, Sleep Medicine
Hasmeena Kathuria, MD - Pulmonology, Critical Care Medicine, Sleep Medicine

Current as ofMarch 25, 2017