What is the normal range for red blood cell count?

The normal range for red blood cell (RBC) count is typically between 4 to 6 million cells per cubic millimeter (mill/mm^3) in adults. This range can vary slightly based on factors such as age, sex, and altitude, but the established normal value for most adults falls within this interval. Having a precise RBC count is crucial for assessing a person's overall health, diagnosing conditions such as anemia or polycythemia, and monitoring various chronic diseases.

The other ranges provided do not align with common clinical standards. Lower ranges like 3-5 million indicate lower counts than what is normally accepted, which would suggest potential health issues. Higher ranges, such as 5-8 million or 6-8 million, exceed normal physiological limits and could indicate conditions that cause excessive red cell production, which may require further investigation. Overall, understanding these ranges helps in the proper assessment and management of a patient's health.