The cause of leukocytosis in acute inflammation is the result of elevated reactivity of the organism in order to remove pathogens that have invaded the body. 1. Acute inflammation is mostly caused by the invasion of bacteria (Streptococcus pneumoniae, Escherichia coli, Staphylococcus aureus, etc.) into the body. When acute inflammation occurs in the body, the body’s immune defense mechanism plays a role, leading to reactive proliferation of granulocytes in the bone marrow, thus generating a large number of white blood cells, mainly neutrophils, which play an anti-inflammatory role in the body. 2. Acute inflammation is accompanied by elevated inflammatory indexes such as calcitoninogen and C-reactive protein, as well as symptoms corresponding to the site of infection and systemic acute infectious symptoms, such as coughing and coughing up sputum, frequent urination and painful urination, and chills and fever, etc. The patient should be treated with antibiotics and active anti-infective treatment. After active anti-infective treatment with antibiotics, the white blood cell count gradually returned to normal.