Sleep apnea is caused by different factors depending on the type: obstructive sleep apnea (OSA) or central sleep apnea (CSA).
Causes of Obstructive Sleep Apnea (OSA)
OSA occurs when the airway at the back of the throat becomes narrowed or blocked during sleep, leading to disrupted breathing. Key causes and risk factors include:
- Excess weight or obesity, which increases soft tissue in the throat that can block the airway during sleep
- Anatomical features such as a narrow airway, large neck circumference, enlarged tonsils or tongue, a short lower jaw, or a narrow upper jaw
- Relaxation of throat and tongue muscles during sleep, which reduces airway space and can cause obstruction
- Aging, which increases risk due to changes in airway anatomy and muscle tone
- Male sex is more commonly affected
- Smoking, which can increase airway inflammation and congestion
- Chronic nasal congestion or other conditions like chronic obstructive pulmonary disease (COPD)
- Family history, suggesting genetic or anatomical predisposition
- Sleeping on the back, which may worsen airway collapse
- Hormonal abnormalities such as hypothyroidism or excess growth hormone, which can cause tissue swelling near the airway
- Use of alcohol and some medications that relax throat muscles
In children, enlarged tonsils or adenoids and certain dental or craniofacial abnormalities can cause OSA
Causes of Central Sleep Apnea (CSA)
CSA is caused by the brain's failure to properly control breathing during sleep, leading to pauses in breathing without airway obstruction. Causes include:
- Problems with the brainstem's regulation of breathing, often due to stroke, heart failure, or other neurological conditions
- Heart failure and related conditions causing unstable ventilatory control
- Older age and male sex increase risk
- Use of opioid drugs and some medications that affect respiratory drive
- High-altitude exposure leading to reduced oxygen availability
In summary, obstructive sleep apnea is primarily caused by physical blockage or narrowing of the airway during sleep, often related to obesity and anatomical factors, while central sleep apnea results from impaired brain control of breathing
