Phlebitis is divided into 0-4 grade a total of 5 grade, 0-5 grade of phlebitis are described as follows: 1, grade 0 performance is no symptoms; 2, grade 1 performance is infusion site redness, with or without pain; 3, grade 2 performance is infusion site pain, with redness or edema; 4, grade 3 performance is infusion site pain, with redness or edema, with striae formation, can be palpable striae vein; 5, grade 4 It shows pain at the infusion site with redness or edema, and a striated vein can be palpated, usually >2.5 cm, often with pus exudation.