The causes of edema caused by patients should be analyzed according to the condition, age, time of edema, and the part of edema, as follows: 1. Kidney disease: it may be accompanied by a longer period of eyelid, face, and lower limb edema obviously, and accompanied by a large amount of foam during urination, which can be proved to be kidney-induced edema through laboratory tests; 2. Heart disease: accompanied by the following symptoms, such as palpitations after the patient’s activity, wheezing, chest tightness, and inability to sleep flat at night, it is suspected that edema may be related to the heart, and some biochemical tests as well as blood BNP and cardiac ultrasound can be done to distinguish it; 3. Liver diseases: liver diseases caused by liver causes, patients may have a history of alcohol consumption and yellow skin, which can also be distinguished through biochemical indicators and liver ultrasound; 4. Other diseases: clinically more common, such as thyroid diseases, the mucinous edema caused by hypothyroidism; edema of the lower extremities caused by problems with the blood vessels of both lower extremities; even edema caused by allergies in some patients, etc. In short, it should be analyzed according to the specific situation of the patient.