Blood oxygen level plays a crucial role in keeping our organs functioning properly. Oxygen saturation measures the percentage of oxygen your red blood cells carry from your lungs to the rest of your body. A normal oxygen level for adults is typically between 95% and 100%. If oxygen levels drop below this range, it is a sign of low oxygen levels or hypoxemia, which can lead to symptoms like shortness of breath and confusion. Common causes of low oxygen levels include lung diseases such as asthma or bronchitis, heart disorders, or high altitudes.