The degree of edema can be graded into 4 grades: 1. edema below the ankle. 2. edema below the knee. 3. edema below the hip. 4. body edema. In addition to grading in clinical practice, the degree of edema can also be divided into 3 degrees: mild, moderate and severe. Mild edema occurs only in areas with loose tissues, such as the soft tissues below the eyelids and orbits, and the subcutaneous tissues of the ankle. In moderate edema, edema can be seen in loose tissues all over the body, and there will be depressions after pressure, and recovery will be very slow.