Increased neutrophil percentage is commonly caused by infections and inflammation, trauma, bleeding, metabolic disorders, immune disorders, and other causes. Neutrophils are a type of white blood cell, and the percentage of neutrophils in adults is about 50 to 70 percent of the total number of white blood cells. Neutrophils play an important role in the body’s fight against infection and can move toward invaders, such as parasites and bacteria, etc. Upon contact with an invader, the cytoplasm around the neutrophil bulges to form pseudopods, which encapsulate the invaders and produce a cytotoxic effect to destroy them. In addition to engulfing and destroying invading pathogens, neutrophil membranes release arachidonic acid, which promotes the production of thromboxanes and prostaglandins, among others, and has a marked effect on the regulation of vascular caliber and permeability, as well as eliciting inflammatory responses and pain, and affecting blood coagulation. When the percentage of neutrophils is found to be increased, it is recommended to consult a professional doctor to find out the cause and further diagnosis and treatment, so as not to delay the condition.