Sleep apnea is one of the most common sleep disorders worldwide, yet many people are unaware that it exists in several different forms. Each type affects breathing during sleep in a slightly different way, though the result is the same.
Medical specialists generally identify three main types of the condition: obstructive sleep apnea, central sleep apnea, and complex sleep apnea syndrome.
Obstructive Sleep Apnea
Obstructive sleep apnea (OSA) is the most common form. It occurs when the muscles at the back of the throat relax during sleep and temporarily block the airway. When this happens, breathing either stops completely or becomes extremely shallow.
These breathing pauses often last at least 10 seconds and may occur many times during the night. In moderate or severe cases, interruptions can happen more than 30 times per hour. Each pause reduces the oxygen level in the blood and briefly wakes the brain so that breathing can resume.
People with obstructive sleep apnea frequently snore loudly because air is forced through a partially blocked airway. Other symptoms often include choking or gasping during sleep, morning headaches, and severe daytime tiredness.
Several factors increase the risk of obstructive sleep apnea. Excess body weight is one of the most significant because fatty tissue around the neck can narrow the airway. A naturally narrow throat, enlarged tonsils, smoking, alcohol use, and ageing can also contribute to airway obstruction during sleep.
Central Sleep Apnea
Central sleep apnea is less common. Unlike obstructive sleep apnea, the problem is not caused by a blocked airway. Instead, the brain temporarily fails to send the correct signals to the muscles that control breathing.
During sleep, breathing normally operates automatically through signals sent from the brainstem to the respiratory muscles. In central sleep apnea, this communication becomes unstable, leading to pauses in breathing even though the airway remains open.
People with central sleep apnea may experience symptoms similar to those of obstructive sleep apnea, including frequent awakenings, shortness of breath during the night, and excessive daytime fatigue. Loud snoring is usually less prominent.
Central sleep apnea is often linked to underlying medical conditions such as heart failure, stroke, or certain neurological disorders. It can also occur in people who use opioid medications or who have recently travelled to high altitudes.
Complex Sleep Apnea Syndrome
Complex sleep apnea syndrome, sometimes called treatment-emergent central sleep apnea, is a combination of both obstructive and central sleep apnea. It is typically identified when a patient who is being treated for obstructive sleep apnea begins to show signs of central breathing pauses during therapy.
In these cases, the airway obstruction improves with treatment such as continuous positive airway pressure (CPAP) therapy, yet breathing interruptions still occur because the brain temporarily stops signalling the breathing muscles.
Complex sleep apnea is less common than the other two forms, but it highlights how closely breathing and brain function are connected during sleep.
Why Identifying the Type Matters
Determining which type of sleep apnea a person has is essential for choosing the most effective treatment. Doctors usually confirm the diagnosis through a sleep study, which records breathing patterns, oxygen levels, heart rate, and brain activity during sleep.
Once the specific type is identified, treatment can be tailored accordingly.
Sleep apnea is a serious medical condition, but it is highly treatable when properly diagnosed. Understanding the different types helps people recognise symptoms sooner and take the first step towards healthier, more restorative sleep.
