Adult: Male: 45–52%; SI units: 0.45–0.52. Female: 37–48%;
SI units: 0.37–0.48.
Child: 1–6 yr: 30–40%; SI units: 0.30–0.40; 6–18 yrs: 32–44%;
SI units: 0.32–0.44
Critical Levels: <15% or >60%
. Lavender-top tube.
■ Hematocrit is the percentage of whole blood that is made up
of red blood cells. It is expressed as a percentage or a decimal
fraction. (A hematocrit value of 35% means that there is 35 mL
of red blood cells in 100 mL of blood.)
■ Increased in dehydration and increased production of RBCs.
■ Decreased in anemia, when RBC production is impaired or
there is increased destruction of RBCs, in chronic disease,
blood loss, and fluid volume excess.
■ See Complete Blood Count.
