Blood oxygen levels refer to the amount of oxygen circulating in the blood. Normal blood oxygen levels fall between 75 and 100 millimeters of mercury (mm Hg) on arterial blood gas (ABG) test results.

Vaping has an immediate effect on how well the user’s blood vessels work, even if the e-cigarette doesn’t contain nicotine, according to new research. The research – which has not been published in a ...