Sleep apnoea (also known as obstructive sleep apnoea or OSA) occurs when the throat muscles relax too much during sleep. 

Some of the symptoms of sleep apnoea include: 

• Poor quality sleep – with regular periods of reduced or absent breathing often accompanied by loud snoring and/or gasping for air. 
• Daytime sleepiness and fatigue. 
• Dry mouth and headaches upon waking. 
• Poor concentration, poor memory and slow reaction times. 
• Irritability and mood changes. 
• Depression and anxiety. 
• Impotence (erectile dysfunction) and reduced sex drive (libido). 
• Need to get up to toilet frequently at night.