What is the normal range for white blood cell count per cubic millimeter?

What is the normal range for white blood cell count per cubic millimeter?

• A. 10,000-15,000 per mm
• B. 5,000-10,000 per mm
• C. 1,000-5,000 per mm
• D. 15,000-20,000 per mm

Answer: (B)

Normal white blood cell count is about 5,000 to 10,000 cells per cubic millimeter. This range represents the typical circulating immune cell level in a healthy adult. Counts below 5,000 (leukopenia) can indicate bone marrow suppression, certain illnesses, or overwhelming infections, while counts above 10,000 (leukocytosis) can occur with infections, inflammation, stress, or hematologic disorders. For NBRC-style reference values, 5,000–10,000 per mm3 is the standard normal range, making it the correct choice.

Normal white blood cell count is about 5,000 to 10,000 cells per cubic millimeter. This range represents the typical circulating immune cell level in a healthy adult. Counts below 5,000 (leukopenia) can indicate bone marrow suppression, certain illnesses, or overwhelming infections, while counts above 10,000 (leukocytosis) can occur with infections, inflammation, stress, or hematologic disorders. For NBRC-style reference values, 5,000–10,000 per mm3 is the standard normal range, making it the correct choice.