This is only true for people who live close to sea level. At higher altitudes, saturation even down into the high 80s can be normal: https://www.thelancet.com/j

This is only true for people who live close to sea level. At higher altitudes, saturation even down into the high 80s can be normal: https://www.thelancet.com/journals/langlo/article/PIIS2214-109X(19)30543-1/fulltext https://www.thelancet.com/journals/langlo/article/PIIS2214-1...