Reference values for which test are typically higher for capillary specimens?

The reference values for glucose tested using capillary specimens are typically higher compared to those obtained from venous specimens. This phenomenon can be attributed to several factors related to the physiology of the body's response to blood sampling and the nature of capillary blood.

When a capillary sample is taken, it often reflects the composition of interstitial fluid and can show elevated glucose levels due to the rapid physiological response of the body to actions such as eating or drinking. Additionally, the collection process, which may involve squeezing the finger, can cause a rise in local glucose concentrations by releasing additional glucose from nearby tissues.

Understanding this difference is crucial for phlebotomists and healthcare providers when interpreting test results, as it helps ensure that patient management and diagnoses are based on accurate assessments. All other tests, such as cholesterol, calcium, and electrolytes, do not exhibit the same consistent difference in reference values between capillary and venous specimens, making glucose unique in this respect.