Surgical incision infection is judged primarily by the condition of the incision, and the presence of infection is judged by the presence of redness, swelling, heat and pain in the incision. Patients with infected incisions usually have red, swollen, painful wounds with bloody or purulent exudate, and usually have changes in body temperature, with low or even high fever. The infected part of the incision may feel throbbing and fluctuating to the touch when it becomes septic. Patients with infections should have blood tests promptly. The white blood cells and neutrophils in the blood may be high, and local pressure may be painful.