What is sleep-disordered breathing?

Sleep-disordered breathing is a term you’ll see used a lot when reading about sleep apnea. So, what is sleep-disordered breathing, and how is it related to sleep apnea?

Often referred to simply as SDB, sleep-disordered breathing describes any condition in which breathing is disrupted or abnormal during sleep. It’s a broad term that includes many chronic health conditions related to nighttime breathing disorders. Technically, the various types of sleep apnea — obstructive sleep apnea, central sleep apnea and mixed sleep apnea — are all forms of sleep-disordered breathing.

As we discussed in an earlier blog post, obstructive sleep apnea (OSA) occurs when throat tissue blocks your breathing passage, whereas central sleep apnea (CSA) is caused by the brain’s failure to properly communicate with the respiratory system. Mixed sleep apnea is a combination of both types of the condition.

As the root of all these various types of sleep apnea, as well as other health conditions, sleep-disordered breathing is generally considered to be common among people in the United States.

“Despite the increased awareness of sleep-disordered breathing, it has been suggested that 93 percent of women and 82 percent of men with signs and symptoms of moderate to severe sleep-disordered breathing remain undiagnosed,” according to the American Thoracic Society’s 2010 book “Breathing in America: Diseases, Progress, and Hope,” which refers to  this 1997 Sleep study.¹

And that’s significant, given that SDB and sleep apnea are often associated with other, more serious conditions like cardiovascular disease and diabetes.^2,3

Other forms of sleep-disordered breathing

However, sleep-disordered breathing doesn’t always lead to sleep apnea, and symptoms of one don’t guarantee the presence of another.

“In general, everyone with SDB snores, but not everyone who snores has SDB,” writes Vittorio Rinaldi, MD at Medscape. Dr. Rinaldi goes on to define another form of sleep-disordered breathing that doesn’t fall into the sleep apnea category: upper airway resistance syndrome (UARS).

“[UARS] is characterized by snoring with increased resistance in the upper airway, resulting in arousals during sleep,” Dr. Rinaldi writes, explaining that the condition can disturb sleep “to the point of causing daytime somnolence.” However, even though UARS isn’t the same as sleep apnea, it’s treated similarly: “Patients with UARS can be treated with nasal continuous positive airway pressure (n-CPAP),” Dr. Rinaldi adds.

Sleep-disordered breathing can also be connected to a variety of other respiratory disorders, including obesity hypoventilation syndrome (OHS), a condition involving severe obesity and respiratory dysfunction that shares many symptoms with sleep apnea; a 2007 report in Chest  even classifies OHS as a form of central sleep apnea, along with high altitude-induced periodic breathing and Cheyne-Stokes breathing (CSB).⁴ We’ll talk more about CSB in future blog posts.

If you think you may have sleep-disordered breathing or any of the conditions described in this article, talk to your doctor about whether you should take a sleep test. We also encourage you to take our sleep apnea symptom quiz.

This blog post contains general information about medical conditions and potential treatments. It is not medical advice. If you have any medical questions, please consult your doctor.

References

1. Source: Young T, Evans L, Finn L, Palta M. “Estimation of the clinically diagnosed proportion of sleep apnea syndrome in middle-aged men and women.” Sleep. 1997 Sep;20(9):705-6. https://pubmed.ncbi.nlm.nih.gov/9406321/ (accessed November 5, 2013).
2. Source: Vozoris NT. “Sleep apnea-plus: prevalence, risk factors, and association with cardiovascular diseases using United States population-level data.” Sleep Med. 2012 Jun;13(6):637-44. doi: 10.1016/j.sleep.2012.01.004. Epub 2012 Apr 3. https://pubmed.ncbi.nlm.nih.gov/22475994/ (accessed November 5, 2013).
3. Source: Tasali E, Mokhlesi B, Van Cauter E. “Obstructive sleep apnea and type 2 diabetes: interacting epidemics.” Chest. 2008 Feb;133(2):496-506. doi: 10.1378/chest.07-0828. https://pubmed.ncbi.nlm.nih.gov/18252916/ (accessed November 5, 2013).
4. Source: Danny J. Eckert, PhD, Amy S. Jordan, PhD, Pankaj Merchia, MD, and Atul Malhotra, MD, FCCP. “Central Sleep Apnea: Pathophysiology and Treatment.” Chest. 2007 February; 131(2): 595–607. doi: 10.1378/chest.06.2287. https://pmc.ncbi.nlm.nih.gov/articles/PMC2287191/ (accessed November 5, 2013).