Enteric radiation sickness develops in about 1 week with small bowel crisis. Acute radiation disease (acuteradiationdisease) is a systemic disease caused by the exposure of the body to large doses (1 Gy) of ionizing radiation within a short period of time. Acute radiation disease can occur with both external and internal irradiation, but external irradiation is the main cause. External exposure causes acute radiation sickness with gamma; lines, neutrons and X-rays. Lymphocytes (mainly spleen and lymph nodes) change in a similar pattern as bone marrow, with inhibition of cell division, cell necrosis, reduction and hemorrhage, and develop faster than bone marrow and recover earlier than bone marrow, but complete recovery takes longer time. With the development of hematopoietic lesions, the clinical course of myeloid radiculopathy has obvious stages, which can be divided into the initial stage, pseudo-healing stage, extreme stage and recovery stage. Especially, moderate and severe stages are obvious. 1. Peripheral blood picture (1) The change pattern of white blood cells indicates the stage of disease development. Throughout the course of the disease, there are seven stages of change in peripheral blood leukocyte count. Based on the process of leukocyte changes, the development of the disease can be predicted. (2) The rate and minimum value of leukocyte decline can reflect the severity of the disease. The rate of graded decrease (109/L? d) 7d value after illumination (109/L) 10d value after illumination (109/L) 1109/L time (d after illumination) minimum value (109/L) minimum value time (d after illumination). Mild 4.54.03.0; moderate 0.253.53.020～321.0～3.035～45; severe 0.25～0.62.52.08～201.025～35; very severe 0.61.51.080.521. (3) Those with inverted granulocyte/lymphocyte ratios are considered moderate or higher, and those without are generally considered mild. (4) In addition to quantitative changes, leukocytes also show morphological changes. Neutrophils may show nuclear and plasma vacuoles, cytoplasmic granules, excessive nuclear lobulation, large cells or large nuclei, as well as nuclear spines, nuclear sequestration, and nuclear lysis. Lymphocytes can be seen with nuclear chromatin concentration, nuclear condensation, nuclear fragmentation, nuclear lobulation or binucleation, and atypical lymphocytes in the recovery phase. Morphological changes of platelets may include loss of pseudopods, vacuolar degeneration, reduction of dense bodies (5-HT organelles), and granulolysis. Giant or heterogeneous platelets can be seen in the recovery phase. Red blood cells also have morphological changes, such as uneven cell size, heterotypic and multi-stained cells, and young red blood cells can be seen in peripheral blood during recovery. Bone marrow examination (1) Bone marrow cell division index: Early examination of the bone marrow cell division index (number of divided cells/1000 nucleated cells in the bone marrow) can also help determine the condition. The average bone marrow cell division index in normal men is 8.8 permil; (6.3 permil; ~10.0 permil;). The degree of decrease in myeloid cell division index on day 4 after 0.5-3 Gy irradiation was significantly correlated with the irradiation dose. In general, it is believed that if the bone marrow cell division index is still higher than 1.8 permil 3-4 days after irradiation, it may be mild radiation sickness; if it decreases to 1.8 permil; ~0.9 permil; it may be moderate; if it decreases to 0.8 permil; ~0.2 permil; it may be severe; if it decreases to 0, it is very severe. (2) Bone marrow image: Bone marrow image can be checked once a week during the course of the disease. If the bone marrow image is basically normal, it is mild radiation sickness. Severe suppression of bone marrow appears 20-30 days after irradiation, but to a lesser extent is considered moderate. Severe suppression of bone marrow 15 to 25 days after irradiation is considered severe. Those who appear within 10 days after irradiation are considered to be extremely severe.