There are several types of the condition. These include:
Obstructive sleep apnoea
This happens when the muscles in the back of your throat that support your soft palate, relax.
When the muscles relax, your airway narrows or closes as you breathe in. You can't get enough air, which lowers the oxygen level in your blood. Your brain senses that you can't breathe, and briefly wakes you up, often without you being aware of it, so that you can reopen your airway.
You might snort, choke or gasp. This pattern can repeat itself five to 30 times or more each hour, all night. This makes it hard to reach the deep, restful phases of sleep.
Risk factors for obstructive sleep apnoea include:
- Obesity
- High blood pressure
- Family history of sleep apnoea
- Certain medical conditions
- Age (more common in older adults)
- Gender (men are more likely to be affected than women, but women's risk increases after menopause)
- Large neck circumference Narrowed airway (for example enlarged tonsils)
Central sleep apnoea
This is a less common form of sleep apnoea. It occurs when your brain fails to send signals to your breathing muscles. This means that you make no effort to breathe for a short period, leading to the fall in body oxygen levels. You might awaken with shortness of breath or have a difficult time getting to sleep or staying asleep.
Risk factors for central sleep apnoea include:
- Being older
- Being male
- Having congestive heart failure increases the risk
- Using narcotic pain medicines. Opioid medicines, especially long-acting ones such as methadone, increase the risk of central sleep apnoea
- Having had a stroke increases the risk of central sleep apnoea
Complex sleep apnoea syndrome
This type is a combination of both obstructive and central sleep apnoea.
It may initially appear as OSA and then show signs of central apnoea, especially after starting treatment like CPAP. CPAP, or continuous positive airway pressure, is a treatment commonly used for obstructive sleep apnoea (OSA). It involves a machine that delivers a constant, gentle stream of air through a mask worn over your nose and mouth during sleep.
This steady airflow helps keep the upper airway open, preventing it from collapsing and causing breathing pauses.