# Do Astronauts snore when sleeping in Zero G?

Astronauts often lose their sense of smell, which diminishes the sense of taste. This is because blood flows to their heads owing to the lack of gravity, and this causes their faces to swell and blocks their noses

Which got me thinking what the impact would be on snoring, which in my experience is at least partly based on positioning and gravity effects on soft parts. Does no gravity mean no snoring? Or does the lack of gravity and related soft tissue swelling increase snoring?

I'm not a specialist, but from the documentation available online, it seems snoring is reduced in microgravity.

"Microgravity was associated with a 55% reduction in the apnea–hypopnea index (AHI), which decreased from a preflight value of 8.3 $\pm$ 1.6 to 3.4 $\pm$ 0.8 events/h inflight. This reduction in AHI was accompanied by a virtual elimination of snoring, which fell from 16.5% $\pm$ 3.0 of total sleep time preflight to 0.7% $\pm$ 0.5 inflight"

Source: Microgravity Reduces Sleep-disordered Breathing in Humans ANN. R. ELLIOTT, STEVEN A. SHEA, DERK-JAN DIJK, JAMES K. WYATT, EYMARD RIEL, DAVID F. NERI, CHARLES A. CZEISLER, JOHN B. WEST, and G. KIM PRISK.