Sitting all right a walking shortness of breath is often associated with cardiopulmonary diseases, common causes include pulmonary embolism, cardiac insufficiency, bronchial asthma. 1. Pulmonary embolism: pulmonary embolism refers to the embolus blocking the pulmonary artery and its branches, thus leading to the pulmonary circulation and cardiac dysfunction clinical syndrome, with obesity, lower limbs for a long time stationary, genetic and other factors. Sitting nothing a walk will lead to an increase in oxygen consumption, pulmonary vascular blockage easily lead to insufficient blood supply to the lungs, there will be symptoms of shortness of breath during activities. 2. Cardiac insufficiency: is due to various reasons caused by the decline in the contraction function of the heart muscle, so that the heart to reduce the blood discharge, resulting in blood stagnation in the body circulation or the pulmonary circulation produced by the stifling of symptoms such as asthma, panic, most often occurs in the population suffering from coronary artery disease, when the amount of activity increases that will be the emergence of symptoms of shortness of breath. 3. Bronchial asthma: bronchial asthma due to the high reactivity of the airway, in the activities and physical exercise can lead to airway spasm, obstruction and other phenomena, will also be manifested in the symptoms of shortness of breath. There are many other diseases that cause shortness of breath after activity, such as lung infection, severe anemia, etc., need to consult a doctor in time to clarify the cause of the disease, give targeted treatment.