Phlebitis and vasculitis are two very different diseases. Both diseases cause varying degrees of blood circulation disorders, but the clinical manifestations are very different. Phlebitis (full name thrombophlebitis) is an acute aseptic inflammation of the venous vessels, which can be divided into superficial and deep phlebitis depending on the site of the lesion. Patients often complain of pain and swelling, and a few patients may have fever and increased white blood cell count. There are many causes of phlebitis, such as trauma, surgery, pregnancy, childbirth, oral contraceptives and prolonged standing, squatting, sitting and lying.