There is no specific data on the mortality rate after leukemia relapse, but usually the prognosis is poorer and the survival period is shorter compared to that of non-relapsed ones, so it is recommended to review the disease regularly to reduce the chance of relapse. Leukemia can be divided into acute leukemia and chronic leukemia. 1. Acute leukemia usually starts quickly, and the survival period can be prolonged after effective induction chemotherapy, but if relapse occurs, the survival period is about 1 year, or even life-threatening within a few months. 2. Chronic leukemia usually lasts for a long time and is mainly divided into chronic granulocytic leukemia and chronic lymphocytic leukemia. Chronic granulocytic leukemia, if it enters the acute phase, may have the same rapid onset as acute leukemia, leading to death, and if it relapses, the overall 3-year survival rate is about 59%. Chronic lymphocytic leukemia is an inert form of leukemia that may last a lifetime without treatment, or the disease may progress rapidly and become life-threatening in a short period of time. When leukemia is present, it is important to actively seek medical attention and follow the doctor’s instructions for appropriate treatment.