Medically reviewed by
Dacelin St Martin, MD
Triple board-certified in Sleep Medicine,
Internal Medicine, and Pediatrics.

 
 
Physiology  |  Risk Factors  |  Associated Conditions  |  Signs & Symptoms  |  Diagnostic Tools  |  Complications  |  Treatment

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Introduction

Obstructive Sleep Apnea (OSA) is a common sleep disorder known to have serious implications on a patient’s physical and mental health. If not detected early and managed properly, it can increase the risk of several disorders, including heart attacks, hypertension, and depression. 

OSA is characterized by frequent awakening at night due to interruptions in breathing. In other words, breathing pauses and re-starts repeatedly, preventing patients from having a restful and restorative night’s sleep. ^{[1] [2]}

Read on to know all about OSA, its symptoms, causes, risk factors, and the best methods to diagnose and treat it.

Physiology 

OSA occurs when the muscles in the throat relax intermittently during sleep, leading to a blockage in the air passages. 

Throat muscles are responsible for supporting structures, such as the roof of the mouth (soft palate), the uvula (triangular tissue arising or hanging from the palate), the tongue, and the tonsils. 

The excessive and repeated relaxation of throat muscles causes the tongue to fall back into the air passages, blocking airflow. As a result, the oxygen levels in your blood drop while the carbon dioxide levels increase. These abnormal changes in the blood’s parameters cause the brain to sense an impairment in breathing, rousing the patient from sleep.

Due to these physiological changes, patients with OSA often wake up gasping for breath. This awakening allows airways to reopen and breathing to resume.^[3] This breathing pattern can repeat itself 5 to 30 times (or more) every hour throughout the night. 

Sleep disruptions can impair the ability to have a restful and restorative night’s sleep, resulting in daytime fatigue.

There are 4 phases of sleep that are passed through each night; however, those with OSA cannot reach the most restorative sleep phase, the REM sleep phase. The body is desperately trying to get the oxygen it needs, and as a result, the patient wakes up before they can reach the later phases of sleep.

Risk Factors 

• Gender: OSA is more prevalent in men than women
• Obesity: Excess fat around air passages can obstruct breathing
• Neck Size: More than 17″ in men and more than 16″ in women^{[4] [5]}
• Genetics: The risk of developing OSA is higher amongst first-degree relatives (parent to child)
• Narrow airways due to enlarged tonsils or adenoids 
• High blood pressure 
• Unhealthy habits, such as smoking^[6]

Associated Conditions

There’s a strong likelihood of comorbidity with the following conditions:^[7]

• Obesity
• Chronic nasal congestion due to sinusitis 
• Diabetes
• Asthma
• Tonsillitis
• Hypertension
  
  

Signs & Symptoms

Snoring is a common sign of OSA and occurs as air passes through the obstructed air passages, creating turbulence. People with obstructive sleep apnea may also experience other symptoms:^[8]

• Episodic choking and gasping during sleep 
• Morning Headaches
• Daytime drowsiness 
• Lack of clarity or reduced alertness in the morning 
• Frequent headaches 
• Feeling irritable and angry possibly due to the lack of sleep 
• Forgetfulness
• Hyperactivity, especially in children
• Poor job and academic performance^[9] 
• Swelling in the legs
• Loss of interest in sex
• Increased risk of vehicular accidents due to reduced alertness
  
  

Diagnostic Tools

OSA’s most notable symptoms include frequent awakenings at night, daytime drowsiness, and snoring; however, further physical examination and tests can help confirm a diagnosis. 

During the physical check-up, the doctor will examine the mouth, back of the throat, nose for swelling, enlargement of tissues, or other abnormalities. The doctor might measure the waist and neck circumference and check blood pressure to ascertain OSA’s possible causes.^[10]

Diagnostic Tools

1. Polysomnography (sleep study at a sleep center)
2. Home Sleep studies through companies, like MHSleepTesting.com

An AHI: Apnea hypopnea index of at least 5 in either polysomnography or home sleep study is required to be classified as OSA.

The Severity of Sleep Apnea Based on AHI:
1. AHI of 0-5: No Sleep Apnea
2. AHI: 5-15: Mild OSA
3. AHI: 15-30: Moderate OSA
4. AHI: >30 Severe OSA

Complications

• Daytime drowsiness, irritability, and fatigue lead to difficulties in concentrating. 
• Children and young adults may have poor academic performance and develop attention and behavioral problems.
• Depression and other mental health issues may occur due to the lack of sleep and its effect on daytime productivity and the overall quality of life.^[11]
• A sudden drop in oxygen levels in the blood caused due to OSA might increase blood pressure and create more strain on the heart. This physiological reaction can increase your risk of hypertension, heart attacks, cardiac failure, and stroke.
• Patients with OSA are more likely to have arrhythmias (abnormal heart rhythms) as this condition can interfere with the heart’s normal activities. 
• OSA is linked to a higher instance of eye conditions, like glaucoma. 
  
  

Treatment

OSA can be managed by one of these 3 ways:

1) CPAP
Short for continuous positive airway pressure, this is considered the gold standard for all levels of severity. The CPAP machine consists of a mask that patients wear over the nose or mouth while sleeping. The machine then pumps oxygen into the airways through the mask, thus improving oxygen flow. It allows the airways to remain open while sleeping and reduces the incidences of awakening.

2) Oral Appliances
Oral Appliances or mandibular advancement devices, shaped like a mouth guard, can also be used to treat OSA. This device keeps the airways open while you are sleeping.

3) Surgery
Surgery is necessary for severe OSA cases that cannot be treated with CPAP or oral appliances, like:

• Upper pharyngeal procedures like UPP (uvulopalatopharyngoplasty), adenoidectomy, or tonsillectomy
• Nasal procedures like septoplasty, nasal valve surgery, or rhinoplasty
• Tracheostomy Maxillomandibular advancement surgery
• Lower pharyngeal procedures, like hyoid and tongue suspension, mandibular advancement, or genioglossus advancement
• Upper airway stimulation through the placement of a medical device from a company called Inspire, which keeps airways open with a click of a button

Conclusion

Being aware of OSA symptoms can allow patients to seek early medical intervention and prevent the complications of this disease. Patients are encouraged to speak to their doctor or reach out to a home sleep testing resource.

References:

1. Slowik JM, Collen JF. Obstructive Sleep Apnea. [Updated 2020 Nov 20]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK459252/
2. Arnold, J., Sunilkumar, M., Krishna, V., Yoganand, S. P., Kumar, M. S., & Shanmugapriyan, D. (2017). Obstructive Sleep Apnea. Journal of pharmacy & bioallied sciences, 9(Suppl 1), S26–S28. https://doi.org/10.4103/jpbs.JPBS_155_17
3. Pham, L. V., & Schwartz, A. R. (2015). The pathogenesis of obstructive sleep apnea. Journal of thoracic disease, 7(8), 1358–1372. https://doi.org/10.3978/j.issn.2072-1439.2015.07.28
4. Millman, R. P., Carlisle, C. C., McGarvey, S. T., Eveloff, S. E., & Levinson, P. D. (1995). Body fat distribution and sleep apnea severity in women. Chest, 107(2), 362–366. https://doi.org/10.1378/chest.107.2.362
5. Davies, R. J., & Stradling, J. R. (1990). The relationship between neck circumference, radiographic pharyngeal anatomy, and the obstructive sleep apnoea syndrome. The European respiratory journal, 3(5), 509–514.
6. Krishnan, V., Dixon-Williams, S., & Thornton, J. D. (2014). Where there is smoke…there is sleep apnea: exploring the relationship between smoking and sleep apnea. Chest, 146(6), 1673–1680. https://doi.org/10.1378/chest.14-0772
7. Hoffstein, V., & Szalai, J. P. (1993). Predictive value of clinical features in diagnosing obstructive sleep apnea. Sleep, 16(2), 118–122.
8. Mulgrew, A. T., Ryan, C. F., Fleetham, J. A., Cheema, R., Fox, N., Koehoorn, M., Fitzgerald, J. M., Marra, C., & Ayas, N. T. (2007). The impact of obstructive sleep apnea and daytime sleepiness on work limitation. Sleep medicine, 9(1), 42–53. https://doi.org/10.1016/j.sleep.2007.01.009
9. Hoffstein, V., & Szalai, J. P. (1993). Predictive value of clinical features in diagnosing obstructive sleep apnea. Sleep, 16(2), 118–122.
10. Millman, R. P., Carlisle, C. C., McGarvey, S. T., Eveloff, S. E., & Levinson, P. D. (1995). Body fat distribution and sleep apnea severity in women. Chest, 107(2), 362–366. https://doi.org/10.1378/chest.107.2.362
11. Jehan, S., Auguste, E., Pandi-Perumal, S. R., Kalinowski, J., Myers, A. K., Zizi, F., Rajanna, M. G., Jean-Louis, G., & McFarlane, S. I. (2017). Depression, Obstructive Sleep Apnea and Psychosocial Health. Sleep medicine and disorders : international journal, 1(3), 00012.