Climate change could be disrupting how well you sleep, scientists have found.
That’s because hotter nights caused by the climate crisis could be making sleep apnoea more common – a condition thought to affect about 10 million people in the UK.
People with sleep apnoea often snore loudly, their breathing starts and stops during the night, and they may wake up several times. Not only does this cause excessive sleepiness during the day, but it can also increase the risk of high blood pressure, stroke, heart disease and type 2 diabetes.
Researchers in Australia found that during heatwaves, the number of people suffering from obstructive sleep apnoea (OSA) increases.
Study author Dr Lucía Pinilla from Flinders University said: “During summer heatwaves, obstructive sleep apnoea became more common and more severe. OSA should now be considered alongside other chronic diseases that are worsened by climate change. Heatwaves are not only uncomfortable, but they can also directly affect how we breathe and sleep.”
Previous research has already revealed that rising temperatures can increase heart attacks, suicides and accidents.
One 2022 study, published in the journal One Earth, revealed the average global citizen is already losing 44 hours of sleep a year, with women and older people being the hardest hit.
Researchers at the Adelaide Institute for Sleep Health at Flinders University, in Australia, analysed data on 67,558 people across 17 European countries.
The participants used under-mattress sleep sensors which track sleep patterns, snoring, apnoea events – or pauses in breathing – and heart rate. Most of the participants were male and had an average age of 52 years.
Data from the sleep sensors was tracked from January 2020 to September 2024, covering five summers and compared against local nightly temperatures to assess the impact of heatwaves.
Researchers noted between two and three heatwaves per year on average, with each heatwave lasting around four to five days.
The results published in the European Respiratory Journal found that the risk of people suffering from moderate-to-severe OSA increased by 13 per cent at the peak of a heatwave.
They also found that for every 1C rise in the nighttime temperature during a heatwave, the prevalence of moderate-to-severe OSA also increases by about 1 per cent. The risk was even higher when the humidity was also high.
“These effects are likely to be similar in other parts of the world and may be even more pronounced in regions with hotter climates or more frequent heatwaves,” Dr Pinilla said.
“However, factors like housing quality and access to air conditioning could influence the severity of the impact.”
The team now plans to investigate how hot nights affect breathing during sleep, why OSA worsens and whether cooling strategies or behavioural changes can help reduce the impact.
Professor Sofia Schiza, head of the European Respiratory Society group on sleep disordered breathing, based at the University of Crete in Greece, who was not involved in the research, said: “Obstructive sleep apnoea is a common condition that can increase the risk of serious health problems, such as heart disease and strokes, but many sufferers do not realise they have a problem.
“This research shows how heatwaves, where the temperature remains high overnight, increase the risk of OSA.”
