Sleep tracking has become big business, with devices from Fitbit, Garmin, Whoop, Apple and smart rings like Oura offering detailed "sleep scores" alongside breakdowns of sleep stages. But doctors say the pursuit of a perfect score, dubbed "sleepmaxxing", can tip into "orthosomnia" – an unofficial term for obsessive preoccupation with achieving flawless sleep – and that this anxiety is actually undermining people's rest rather than improving it.

Dr Alanna Hare of the Royal Brompton Hospital says the "sleep score" concept is "completely made up" by manufacturers rather than grounded in recognised sleep science, and that she is seeing more patients arrive with tracker data convinced they have a disorder despite reassuring medical tests. A University of Oxford study found participants given fake, randomised sleep scores still reported greater fatigue and reduced alertness the next day when told they had slept badly, regardless of how they had actually slept. Separately, a proposed lawsuit filed last month in San Francisco alleges Oura's rings cannot accurately measure sleep quality, calling their AI-based estimates no better than "a coin flip"; Oura says it stands behind its science and accuracy claims. One user, 32-year-old Jess Hill, described being "obsessed" with her Garmin's sleep scores for three years before realising the readings weren't matching how she actually felt.