Oxygen 80 refers to arterial oxygen saturation of 80% (normal blood oxygen saturation ≥ 98%), sleeping oxygen 80 significantly lower than normal, suggesting hypoxia, may be respiratory diseases (such as chronic obstructive pulmonary disease, etc.), cardiovascular system diseases (such as heart failure, etc.), poisoning status (such as carbon monoxide poisoning, etc.), need to be specifically analyzed. 1. Respiratory diseases: respiratory diseases such as chronic obstructive pulmonary disease (COPD) can lead to hypoxia due to continuous airflow limitation, resulting in ventilation/blood flow imbalance and other reasons, thus resulting in a decrease in oxygen saturation. 2. Cardiovascular system diseases: cardiovascular system diseases such as heart failure, etc., can be due to cardiac ejection dysfunction, resulting in tissue and organ ischemia, blood stasis in the circulation, resulting in a hypoxic state, and a decrease in blood oxygen saturation. 3. Poisoning: In carbon monoxide poisoning, a large amount of carbon monoxide is combined with hemoglobin to form a large amount of carboxyhemoglobin, so that hemoglobin loses its original oxygen-carrying capacity, resulting in hypoxia and a decrease in blood oxygen saturation. Sleeping oxygen 80 is an abnormal state, it is recommended to consult a doctor in time to clarify the cause of the disease, to avoid delaying the condition.