The science behind the quest to determine the age of bruises-a review of the English language literature.

Bruises are common injuries that can have medicolegal significance. There are those that maintain it is not possible to estimate the age of bruises. However, appreciation of the biological processes related to the resolution of a bruise suggests that these may provide information regarding the age of a bruise. Potential methods for determining the age of bruises-visual observation, colorimetry, spectrophotometry and histology-are reviewed. The observation of yellow (not orange or brown) indicates a bruise is not recent, but the abilities of visual observation are limited by the physiology of the human eye. Analysis of spectrophotometric data may provide more useful and objective information. Histological examination may be appropriate only in the postmortem situation. The lack of published information limits this as a tool for estimating the age of bruises. It is not known how the wide range of factors that can influence bruise formation and resolution could affect estimation of bruise age.