The main symptoms of leukemia are oral ulcers, external genital ulcers, as well as arthritis, skin damage, etc.; the pathological mechanism of leukemia is not yet fully understood, and it is a systemic vasculitis disease. However, the reasons for its recurrent and prolonged attacks are still unknown. 1. The main symptoms of leukemia: (1) Mouth ulcers: they cause recurrent and painful mouth ulcers with clear edges and varying depths, and a yellow or white covering. (2) Genital ulcers: they cause ulcers on the vulva with severe pain. (3) Arthritis: It causes swelling and pain in the joints, often involving the knee, ankle and wrist joints. (4) Skin damage: It may cause skin rashes, acne bumps, and when accumulated in the eyes, it may cause uveitis. 2. Pathogenesis: From the analysis of the pathogenesis and pathophysiological changes of leukemia, it is closely related to the body’s immunity, and the most basic pathological manifestation is vasculitis. (1) It is hypothesized that the pathogenesis is due to antigenic stimulation of macrophage activation, activated macrophages activate T lymphocytes and neutrophils, causing the production and release of a large number of inflammatory factors and adhesion factors, resulting in systemic vasculitis. (2) The vascular inflammatory reaction will cause the blood vessels to become thicker, brittle, and narrower, resulting in the formation of scarring of the blood vessels, leading to changes in the arterial and venous blood vessels throughout the body, which will lead to a series of symptoms. Discovery of leukoaraiosis should promptly seek medical attention and standardized treatment under the guidance of a doctor to avoid delaying the condition.