When we sleep our breathing changes and the airways airway narrow:
- Mucus build up in swollen airways.
- You may cough which triggers more airway narrowing.
- Wakening you from sleep.
Sinus problems can make sleep worse. During the night you may experience increased sinus drainage. This is when mucous drains from your sinus cavities into your throat. However some of this mucous trickles into your airways which can trigger sensitive airways to narrow further.
Lying flat can affect your breathing by:
- Increasing sinus drainage.
- Increasing blood flow to the lung which makes them heavier and the airways can become compressed.
- Reduced volume of air moving in and out of the lungs.
- Your diaphragm moves less when you lie flat.
- Increase in the airway resistance. This can be made worse by Gastro-Oesophageal Reflux Disease, causing heart burn. If the reflux trickles into the airway, spasm can be aggravated by lying flat.