Blood oxygen levels refer to the amount of oxygen carried by red blood cells in the bloodstream. This is crucial for the body, as oxygen is needed for cells to produce energy. Normal blood oxygen levels typically range from 95% to 100%, measured using a device called a pulse oximeter. Low blood oxygen levels, known as hypoxemia, can lead to symptoms like shortness of breath, confusion, or fatigue. Various factors, such as lung diseases, high altitudes, or certain medical conditions, can affect these levels. Monitoring blood oxygen is important for maintaining overall health and ensuring the body functions properly.