Concept of the "Normal Range" in Physiology


* Biological parameters always vary around some "normal set-point"

* No biological parameter ever stays at a constant value

* The normal range includes approx. 95% of a stated normal population

* Sex (M/F) may influence the values of the normal range

* Age, ethnicity, and culture may influence the normal range in human populations

* Reproductive status can alter values of the normal range

* Some normal individuals will always be "low" or "high"

* Drugs may alter values of parameters measured in blood tests

* Different laboratories will have different "normals"

* Handling of blood samples influences end results


* Normal ranges for many medical parameters in humans

* Another source for normal ranges in humans

* What is the normal range????

* Normal Feline and Canine Blood Chemistry Values

* Reference values for many animals

* Typical display of veterinary blood values