A 30-year-old man fell from his motorcycle when he was on the way to office. He complained that his right arm was very painful and suspected right arm humerus fracture. A nearby person immediately called for an ambulance.

Initial assessment by doctor and paramedics revealed loss of one to half liter of blood. Other findings include:

  • Skin appears cold and clammy.
  • His pulse and blood pressure was 90 beats/min and 106/76 mmHg, respectively.

Loss of blood can lead to changes in pulse and blood pressure. These changes are due to initiation compensatory mechanisms by neural regulation activation.