India, Sept. 19 -- After a certain age, snoring gets normalised in most households, and the exhaustion that comes with it goes unrecognised, put down to work or age. Sleep physicians in Delhi describe patients who reach a clinic for the first time three to six years after symptoms begin, pushed often by the person who sleeps beside them and has noticed the pauses in breathing, rather than the noise.

"They try adjusting sleep habits, cutting caffeine, buying a new mattress - everything except getting tested," said Dr Akshay Budhraja, Aakash Healthcare.

Many others turn up for something else altogether - blood pressure that will not come down on medication, diabetes that will not settle - and the apnoea surfaces while the history is being...