Depends on your %.
Saturation levels between 95-100% at sea level are considered "normal." It is BAD for your body to have oxygen saturation levels that fall below 90% for an extended period of time, as it stresses your body and organs, including your heart & lungs. Under Medicare & most insurers in the US, you qualify for supplemental O2 if your oxygen saturation levels drop to 88% or lower during sleep, exertion or sitting. Your doctor should prescribe it & you should use it as prescribed.
Low saturation (59%-88%) means you could have a respiratory disorder.