“What causes low oxygen in the blood?”

Low oxygen in the blood is caused by low oxygen in the breathed-in air. It could also be caused by damage to the lungs which prevents oxygen from entering the blood stream.

Hello. I am not sure why you are asking this question. Our bodies have excellent systems to maintain oxygen levels in the blood. The levels depend on the usage of oxygen by our activity. It is usual that even with strenuous activity the oxygen level does not vary significantly. The lungs are excellent in replenishing oxygen content and disposing of waste gases such as carbon dioxide. Severe lung disease, though, can impede normal functioning of the lungs. Heart disease which can cause fluid buildup in the lungs can also cause a decreased functioning of the lungs which can cause low oxygen concentrations. Your body will react and a person can feel short of breath in these situations.

Anything that prevents oxygen from travelling from the air to the lungs or an abnormal hemoglobin which does not bind oxygen properly. Heart failure also does not move blood fast enough to oxygenate. Most cases due to lung disease