Causes - Obstructive sleep apnoea

Muscles and soft tissues in the throat relax and collapse to some degree while sleeping. For most people, this does not cause breathing problems.

If you have obstructive sleep apnoea (OSA), the airway has narrowed. There are a number of reasons the airway might narrow including:

If you are overweight

Too much body fat increases the bulk of soft tissue in the neck. This can place a strain on the throat muscles.

Too much stomach fat can also lead to breathing difficulties. This can make OSA worse.

Read more about how to eat well

If you are male

OSA is more common in men than in women. It may be related to different patterns of body fat distribution.

Over 40s

OSA can happen at any age. But it's more common in people who are over 40.

Neck structure 

Men with a collar size of more than 43cm (17 inches) have a greater risk of developing OSA.

You are also at a greater risk if you have:

  • a narrow airway
  • large tonsils, adenoids or tongue
  • a small lower jaw

Taking sedative medicines

Taking medicines with a sedative effect can narrow your airway. These include sleeping tablets or tranquilizers.


Drinking alcohol, particularly before going to sleep, can narrow your airway. This can make snoring and sleep apnoea worse.

Read more about alcohol and health


You're more likely to develop sleep apnoea if you smoke.

Read more about stopping smoking

The menopause

Hormone levels change during the menopause. This may cause the throat muscles to relax more than usual.

Family history

There may be genes inherited from your parents that can make you more susceptible to OSA.

Nasal congestion

OSA occurs more often in people with nasal congestion. For example, a deviated septum. This is where the tissue in the nose that divides the two nostrils is bent to one side.

Content supplied by the NHS and adapted for Ireland by the HSE

Page last reviewed: 22 December 2020
Next review due: 22 December 2023

This project has received funding from the Government of Ireland’s Sláintecare Integration Fund 2019 under Grant Agreement Number 123.