Types of sleep apnea

There are three main types of sleep apnea. The type matters, because treatment differs.

Obstructive sleep apnea (OSA) The most common type, accounting for most cases. The throat muscles relax and the airway collapses during sleep, while the chest and belly keep trying to breathe. It causes loud snoring, gasping and daytime sleepiness. It is linked with excess weight, a narrow airway and alcohol.

Central sleep apnea (CSA) The brain fails to send signals to the breathing muscles, so there is no effort to breathe. Snoring may be less prominent. It is more common in people with heart failure, stroke, kidney failure, those on opioid medicine and at high altitude. Treatment focuses on the underlying cause.

Complex (mixed) sleep apnea Occurs when someone has obstructive apnea that turns into central apnea during treatment with a CPAP machine. It needs specialist care.

By severity (apnea-hypopnoea index, AHI) The number of breathing pauses or shallow breaths per hour of sleep:

• Mild: 5 to 14 per hour.
• Moderate: 15 to 29 per hour.
• Severe: 30 or more per hour.

Positional sleep apnea Breathing problems happen mainly when lying on the back and improve when sleeping on the side.

Sleep apnea in children Mostly obstructive, and often due to enlarged tonsils and adenoids.

Related conditions Simple snoring (without pauses), upper airway resistance syndrome and obesity hypoventilation syndrome can look similar, and need assessment.

Ayurvedic view (interpretive) Traditional texts discuss snoring and sleep disturbance under Kapha-related patterns. These categories do not match the medical types above.

Remember A sleep study tells which type you have and how severe it is. Do not guess based on snoring alone.