The novel coronavirus can invade the alveoli of the lungs after infection. When the alveolar structure is damaged by coronavirus, it mainly affects the oxygen and blood exchange function of human, which can affect the normal oxygen entry into the blood, and the human body will have the symptoms of hypoxia. After the onset of hypoxia, a person may feel chest tightness or shortness of breath, and in severe cases, there may be involvement of secondary respiratory muscles, such as intercostal muscles, sternocleidomastoid muscles, and diaphragm. If the hypoxia is severe there may also be terminal cyanosis of the extremities, such as the fingers, toes, and earlobe areas of the ears may appear to turn purple. These changes or manifestations indicate that the patient is in respiratory distress or that the disease has progressed to a certain level. It often indicates that the patient’s condition is more serious. When a family member is found to have similar manifestations, the patient should be taken to the hospital at the first opportunity, or 120 should be called urgently to send to the hospital for medical attention. Content source: Dr. You Lai