The most common clinical reason for this is to consider infectious diseases, such as bacterial infections of the respiratory tract, digestive tract, urinary system, and soft tissues of the skin. If the bacteria in the body are not completely killed, the body will have recurrent fever and increased white blood cells, as well as sepsis, salmonella infection, and rheumatic fever. Secondly, non-infectious diseases, such as hematological diseases, leukemia, especially acute granulocytic leukemia, may cause abnormally high white blood cells and fever. Lastly, autoimmune diseases and connective tissue diseases may have high white blood cells, and antibiotics are not effective in treating these diseases. If you have high white blood cells and repeatedly have high fever, it is advisable to stay in the hospital for examination and clear diagnosis for treatment of the cause.