A method of detecting bleeding from a wound including: providing, on a support, a substantially non-volatile agent capable of forming a volatile agent on contact with blood; disposing the non-volatile agent on the support at or near the wound; providing a probe for detection of the volatile agent; disposing the probe for detection of the volatile agent at a distance from the support; generating a flow of air in a direction from the support to the probe; monitoring the formation of volatile agent by the probe, thereby detecting a bleeding of the wound. Also disclosed are a system and a disposable device for use in the method.