1. Check yourself once a month by touching the neck, armpits, etc. to check whether there are enlarged lymph nodes and whether there is any pressure and pain when pressed. 2. Smokers should pay special attention to the mouth and tongue to see if there are white patches. 3.When coughing for a long time, you should pay attention to whether the sputum coughed up is mixed with blood, pay attention to the time of coughing, the part of chest pain, the amount of blood, the color of blood, etc.. 4, long-term hoarse voice, look in the mirror, open mouth breathing, pay attention to observe the pharynx with or without swelling. 5, many people are keen to lose weight, do not have to work hard to lose weight is indeed gratifying, but if neither increased exercise in a month, and did not reduce the diet, the weight is inexplicably decreased by 10%, then you should promptly consult a doctor. If accompanied by nausea, vomiting, we should pay attention to observe whether there are black-brown contents in the vomit, as well as whether there is a change in the shape of the stool. 6, women after menstruation 1 week, to look in the mirror to observe their own breasts whether there is a lump, if so, to see the hardness of the lump, whether the skin with the adhesion of the condition, there is a lump in the same side of the armpit of the lump whether there is an enlarged lymph node. 7.When there is pain in limbs and limitation of activities after strenuous activities, you should pay attention to check whether there are lumps in joints of your limbs. If painless lumps appear in the long bones, you should go to the hospital for further examination. 8.When fever occurs for a long period of time for unknown reasons, you should pay attention to measure the body temperature at any time, and do blood routine, blood consciousness and other tests if necessary. 9, pay attention to the changes of moles on all parts of the body surface at any time, and observe whether they grow rapidly and break down in a short time, or suddenly appear as lumps, pigmentation, and obvious changes.