As most couples know to their cost, it is all too easy to raise one's partner's blood pressure while awake. Now scientists have shown that we may be liable to do it in our sleep, too.
A study of the effect of noise on sleep has found that a snoring partner can raise a sleeper's blood pressure by as much as a low-flying aircraft or a lorry reversing in the street.
Scientists who monitored 140 volunteers in their homes near Heathrow and three other European airports found the noises penetrating the bedroom had the same effect as those emanating from the neighbouring pillow.
Blood pressure went up in direct relation to noise loudness, by 0.66 mm Hg for every five-decibel increase, the researchers say in the European Heart Journal. The type of sound or its origin did not appear to be important. It was only the volume that mattered.
Lars Jarup, an author of the study from Imperial College London, said: "We know that noise from air traffic can be a source of irritation, but our research shows that it can also be damaging for people's health. This is particularly significant in the light of plans to expand international airports."
He added: "Our studies show night-time aircraft noise can affect blood pressure instantly and increase the risk of hypertension."
High blood pressure is a known risk factor for stroke, heart disease, kidney disease and dementia.