Lymphoma invading bone marrow is lymphoma stage IV. The following manifestations can occur after lymphoma invades bone marrow: 1) dizziness and weakness, which are mainly related to the obstruction of hematopoiesis caused by lymphoma invading bone marrow; 2) leukopenia, which can lead to a decrease in immunity of the patient, and in severe cases, granulocyte deficiency and severe bacterial infections; 3) bleeding in the skin and mucous membranes caused by reduced platelets. In severe cases, bleeding from important organs, such as intracranial hemorrhage and blood in urine and stool, can occur. In conclusion, lymphoma invasion of bone marrow is a very common complication of lymphoma, mainly due to anemia, leukocyte reduction and thrombocytopenia caused by complete blood cytopenia.