The hazards of low hematocrit measurement include anemia, hypoxia, menstrual disorders, poor mental status, etc. In serious cases, it may increase the burden on the heart and cause damage to the heart muscle, and the hazards of different etiologies are different, such as low indicators caused by acute leukemia, which is easy to endanger the life of the patient, and the specific situation should be considered according to the hematocrit value and the patient’s underlying disease conditions. 1. Anemia and hypoxia: low erythrocyte hematocrit indicates that the hemoglobin content in the blood is insufficient, and symptoms related to anemia, such as dizziness, fatigue, pale lips and so on, appear. Secondly, hemoglobin in red blood cells is an important substance for transporting oxygen. Reduced hemoglobin will lead to a decrease in the oxygen-carrying capacity of red blood cells, which will lead to tissue hypoxia, followed by chest tightness, shortness of breath, gastrointestinal discomforts and other symptoms. 2. Menstrual disorders: For women of childbearing age, low hematocrit may cause symptoms such as decreased menstrual flow, irregular menstrual cycles, and in severe cases, amenorrhea. 3. Poor mental state: low hematocrit reduces the blood volume of the whole body and the blood supply to the brain tissue is insufficient, so the patient may suffer from hair loss, lack of concentration and emotional irritability. 4. Danger of primary diseases: low hematocrit caused by acute leukemia, aplastic anemia, systemic lupus erythematosus, etc. can easily lead to severe anemia, severe infections, severe immune response syndrome, etc., which can easily aggravate the condition and endanger the life. Low hematocrit can lead to abnormalities in various aspects of the body, so patients should go to regular hospitals for regular checkups, and if abnormalities occur, they should be treated under the guidance of physicians in a timely manner to avoid adverse consequences.