Self-testing methods for lung function include the blowing test, breath-holding test, stair-climbing test, exercise test, and candle-blowing test. 1. Blow test: It means to inhale deeply and blow vigorously after inhaling enough to see how long it takes to blow out. Generally normal people can blow 70%-80% or even close to 90% in the first second, and 3-4 seconds can be completely blown out. If you can blow out in this period of time, it means that the lung function is normal; severe chronic obstructive pulmonary disease patients may need 6-7 seconds or even longer to blow out completely; patients with expiratory dyspnea and patients with chronic obstructive pulmonary disease can use this method to test. 2. Breath-holding test: It means holding the breath in the resting state. If the breath-holding can reach 30 seconds, it means the lung function is relatively good. 3. Climbing test: If there is no obvious shortness of breath when climbing up to the 3rd floor, it means that the lung function is relatively good. 4. Exercise test: It means walking or running fast in the same place, so that the pulse rate reaches 100-120 beats/min. If the pulse returns to normal in a relatively short period of time after stopping the activity, it means that the cardiopulmonary function is relatively good. 5. Candle blowing test: It means to light a candle and blow it out, the farther away you can blow it out, the better your lung function is. Patients with poor lung function may not be able to blow out the candle at a distance of 15-20cm, which often indicates that lung function is relatively poor. In summary, the lung function self-test more ways, such as abnormalities can go to the hospital to follow the doctor’s instructions for examination and clarification.