How to check your blood oxygen level or the Oxygen saturation? Blood oxygen levels indicates the level of oxygen present in the blood that flows through arteries of the body. Or it is the amount of oxygen circulating in the blood. Most of the oxygen is carried by red blood cells from lungs to the different parts of the body. What is normal and low oxygen level? A normal oxygen level or oxygen saturation means that a person has enough oxygen saturation and flow of oxygen to your different parts of the body through red blood cells. If your oxygen level is low then it means your body has difficulty of delivering oxygen to your body cells, organs. A normal oxygen level varies between 70-100 millimetre of mercury (mm Hg) An oxygen level below 65 is considered as low oxygen saturation and it may be a sign of a condition known as Hypoximia. How your blood oxygen level is measures? The most effective way to monitor blood oxygen levels is an arterial blood gas or ABG test. For this test