Intestinal radiculopathy presents with small bowel crisis in about 1 week. Acute radiation sickness (acuteradiationdisease) is a systemic disease caused by exposure of the body to a large dose (1Gy) of ionizing radiation in a short period of time. Acute radiation sickness can occur with both external and internal exposure, but external exposure is the main cause. The rays that cause acute radiation sickness from external exposure include gamma;rays, neutrons, and X-rays. Lymphocyte (mainly spleen and lymph nodes) change rule is similar to the bone marrow, also to cell division inhibition, cell necrosis, reduction and hemorrhage, its development is faster than the bone marrow, the recovery is also earlier than the bone marrow, but the complete recovery needs a longer time. With the development of hematopoietic organ lesions, the clinical process of myeloid radiculopathy has obvious stages, which can be divided into the initial stage, false healing stage, extreme stage and recovery stage. Particularly obvious are the moderate and severe stages. Therapeutic irradiation High-dose irradiation given to patients for therapeutic needs can cause therapeutic acute radiation sickness. For example, high-dose (6Gy) whole-body irradiation or whole-body lymph node irradiation is commonly used as pretreatment before bone marrow transplantation. Hematopoietic injury is characteristic of bone marrow radiculopathy and it occurs throughout the course of the disease. Reduced cell division index, dilated and congested blood sinusoids are seen in the bone marrow immediately after a few hours of irradiation. This is followed by bone marrow cell necrosis, hematopoietic cell reduction, blood sinus seepage and rupture, and hemorrhage. Hematopoiesis of the erythroid lineage precedes that of the granulomatous lineage, initially with a decrease in naïve cells, and later with a decrease in mature cells. The degree of bone marrow changes is related to the irradiation dose, irradiation dose is small, blood cells only slightly reduced, bleeding is not obvious. If the irradiation dose is large, the hematopoietic cells are severely deficient, or even completely disappeared. Only adipocytes, reticulocytes and plasma cells remain, lymphocytes can be relatively increased, others such as tissue basophils, osteoclasts, osteoblasts are also increased, and there is severe hemorrhage, presenting the phenomenon of severe suppression of bone marrow. After the destruction of bone marrow, if enough hematopoietic stem cells are retained, hematopoiesis can be rebuilt. The recovery of bone marrow hematopoiesis can be started in the third week after irradiation, and the obvious regeneration can be recovered in 4~5 weeks after irradiation. Hematopoiesis often does not recover on its own if the irradiation dose is high. The change rule of lymphocytes (mainly spleen and lymph nodes) is similar to that of bone marrow, with cell division inhibition, cell necrosis, reduction and hemorrhage, its development is faster than that of bone marrow, and its recovery is earlier than that of bone marrow, but it takes a longer time for complete recovery. With the development of hematopoietic organ lesions, the clinical process of myeloid radiculopathy has obvious stages, which can be divided into the initial stage, false healing stage, extreme stage and recovery stage. Particularly pronounced are the moderate and severe stages.