Functio laesa

For other uses of the word dysfunction, see Dysfunction (disambiguation).

Functio laesa, simply known as dysfunction is a term used in medicine to refer to a loss of function^[1][2] or a disturbance of function.^[3]

It was identified as the fifth sign of acute inflammation by Galen, who added it to the four signs identified by Celsus (tumor, rubor, calor, and dolor).^[4]

The attribution to Galen is disputed,^[3] and has variously been attributed to Thomas Sydenham^[5] and Rudolf Virchow.^[6]