Bruising generally refers to the manifestation of subcutaneous petechiae, usually caused by bleeding from tiny blood vessels. Bleeding is a common symptom in patients with leukemia and may form petechiae on the body surface. In most cases, there is no significant difference between bruising caused by bleeding in leukemia and other diseases, and when the skin only shows bruising, it cannot be used as a specific symptom to discriminate between leukemia and other diseases. When there are bleeding spots on the skin, the possibility of leukemia can be suspected. It is recommended to combine other symptoms and the results of auxiliary tests such as blood routine, blood biochemistry and immune function to determine the type of disease and to consult a hospital as soon as possible. Leukemia patients with bleeding manifestations are mostly due to inhibition of normal hematopoietic function of bone marrow and reduction of platelets. Bleeding can occur all over the body, mostly manifesting as multiple scattered bleeding spots under the skin, forming petechiae or petechiae, which are known as bruises. In addition, patients with leukemia often have bleeding symptoms such as nasal bleeding, gum bleeding, bleeding from the fundus of the eyes and increased menstrual flow in women. In addition to bleeding symptoms, patients with leukemia often have clinical manifestations related to infection and anemia, such as fever, pallor, and weakness. In addition, bleeding disorders such as trauma, abnormal blood vessel walls, and coagulation dysfunction may present with skin bruising manifestations due to bleeding bruises caused by abnormal blood vessel walls and coagulation dysfunction caused by trauma. Leukemia patients are often accompanied by bleeding dots on the skin mucosa, and in the middle of the bruise, the bleeding dots are densely distributed, usually in a pinpoint state, while bruises caused by other diseases, such as those caused by trauma, are often accompanied by painful pressure due to the rupture of small blood vessels, and do not fade when pressed. If patients often have unexplained skin bruises, they should go to the hospital early to improve the relevant examination and early treatment to avoid delaying the disease.