Severe anemia

The so-called anemia refers to the hemoglobin in the unit volume of circulating blood, the red blood cell count or hematocrit (hematocrit) is lower than the lower limit of the normal value. This normal value can vary due to different genders, ages, altitude differences in living areas, and changes in physiological plasma capacity. The severity of anemia can be divided into four levels according to the hemoglobin content. Severe anemia is hemoglobin 60 g / l ~ 31 g / l, and he is flustered and short of breath at rest.