1.Superficial abscess is slightly higher than the body surface, with redness, swelling, heat, pain and fluctuating sensation. In small abscesses with deep location and thick cavity wall, the fluctuating sensation may not be obvious. 2.Deep abscesses generally have no fluctuating sensation, but the abscess surface tissue often has edema and obvious local pressure pain, accompanied by systemic toxic symptoms. Acute bacterial endocarditis: mainly the clinical manifestations of sepsis, especially when the heart does not have murmurs, the disease is often masked by the primary infection, easy to miss the diagnosis, for more than a week of fever, need to pay attention to cardiac auscultation changes, skin bleeding spots and embolism phenomenon. It is often differentiated from influenza, acute arthritis, acute septic meningitis, acute pyelonephritis, etc. In recent years, due to the progress of cardiac surgery and the widespread use of antibiotics, there is an increasing trend of atypical or specific types of infectious endocarditis, such as prosthetic valve replacement, hemodialysis or corrective surgery for precardiac disease, all of which increase the chance of endocardial infection, and patients with postoperative fever should be alerted.