The severity of the infection in the double lower lung depends on the cause of the disease itself. Clinically, the infection in the double lower lung is due to common bacteria and viruses, which are generally not serious diseases and can be completely cured by appropriate anti-inflammatory treatment. In contrast to other infections such as leptospirosis, protozoa, parasites, and infections by pathogens such as Mycobacterium tuberculosis and fungi, the inflammation that causes the apparent inflammation of the double lower lung is relatively severe. Because the inflammatory response of these pathogens is very strong and not easily killed, a longer course of anti-inflammatory drug therapy is needed, 1-2 months in the short term and possibly 1.5-2 years in the long term.