As a subject matter expert in respiratory health, I can explain that low oxygen levels, medically referred to as hypoxemia, indicate a situation where the level of oxygen in the blood is below the normal range. This can occur due to a variety of causes, which may include lung problems, heart issues, or issues with the body's ability to transport oxygen. Normally, when breathing room air, the oxygen saturation level in the blood should be between 95 to 100 percent. Hypoxemia can result from a defect in the brain's control over breathing, which is critical for maintaining the right balance of oxygen in the body. read more >>

Low blood oxygen, known as hypoxemia, means that the level of oxygen in the blood has fallen below normal levels, due to one or more of many different causes. Under most circumstances, breathing room air, normal readings range from 95 to 100 percent. ... A defect in the brain's control over breathing.read more >>