How long an elderly person can live with heart and lung failure depends on the specific analysis of each case, because each patient has different underlying diseases, different compensatory mechanisms and resistance to disease, some patients may have life-threatening conditions within a few days, and some patients can survive for a longer period of time, as follows: 1. Life-threatening conditions may occur within a few days: If the patient has severe heart and lung failure, clinically manifested as respiratory distress, hypoxemia, etc., and even bilateral lower limb edema. If the patient’s blood gas analysis is accompanied by severe metabolic acidosis, the condition is more critical and the patient’s life may be in danger within a few days. 2. Longer survival: Some patients with cardiopulmonary failure will improve after receiving timely treatment. If the patient is more compliant and the family situation is more supportive of the disease treatment, he can survive with the disease for a long period of time, even up to decades, through his own exercise and maintenance.