Enteric radiation sickness develops in about 1 week with small bowel crisis. Acute radiation sickness is a systemic disease caused by the exposure of the body to a large dose (1 Gy) of ionizing radiation within a short period of time. Acute radiation sickness can occur with both external and internal exposure, but external exposure is the main cause. External irradiation causes acute radiation sickness with gamma; rays, neutrons and X-rays, etc. Lymphocytes (mainly spleen and lymph nodes) are similar to bone marrow in terms of cell division inhibition, cell necrosis, reduction and hemorrhage, and they develop faster and recover earlier than bone marrow, but it takes longer to recover completely. With the development of hematopoietic organ lesions, the clinical course of myeloid radiculopathy has obvious stages, which can be divided into initial, pseudo-healing, extreme and recovery stages. Especially, moderate and severe stages are obvious. The diagnostic methods are as follows: 1. Peripheral blood picture; The pattern of changes in white blood cells indicates the stage of disease development. There are seven stages of change in peripheral blood leukocyte count throughout the course of the disease. The progression of the disease can be predicted based on the course of leukocyte changes. (1) increase; (2) decrease; (3) stuttering back up; (4) nadir; (5) recovery; (6) excessive increase; (7) return to normal. The rate of decline of white blood cells and the minimum value can reflect the severity of the disease. 2. Bone marrow examination; 3. Biochemical examination.