The circulatory system distributes blood to all parts of the body, carrying oxygen and nutrients to the tissues.  If the circulatory system fails, and insufficient oxygen reaches the tissues, the medical condition known as shock occurs.  If the condition is not treated quickly, the vital organs can fail, ultimately causing death.  Shock is made worse by fear and pain.

Shock can develop as a result of a reduction in the volume of fluid circulating around the body.  The most common examples of this are external or internal bleeding, or loss of other bodily fluids through severe diarrhoea, vomiting, or burns.  The blood supply is diverted from the surface to the core of the body.  The main symptoms and signs of shock relate to such redistribution of the circulation.

Initially, a flow of adrenaline causes:

  • A rapid pulse
  • Pale, grey skin, especially inside the lips.  If pressure is applied to a fingernail or earlobe, it will not regain its colour immediately
  • Sweating, and cold, clammy skin (sweat does not evaporate).

As shock develops, there may be:

  • Weakness and giddiness.
  • Nausea, and sometimes vomiting.
  • Thirst.
  • Rapid, shallow breathing.
  • A weak, ‘thready’ pulse.  When the pulse at the wrist disappears, fluid loss may equal half the blood volume.

As the oxygen supply to the brain weakens:

  • The casualty may become restless, anxious and aggressive.
  • The casualty may yawn and gasp for air (‘air hunger’).
  • The casualty will eventually become unconscious.
  • Finally, the heart will stop.

Treatment of Shock 

DO NOT let the casualty move unnecessarily, eat, drink, or smoke.

DO NOT leave the casualty unattended.  Reassure the casualty constantly.

  • Treat any cause of shock which can be remedied (such as external bleeding).
  • Lay the casualty down, keeping the head low.
  • Raise and support the casualty’s legs (be careful if suspecting a fracture).
  • Loosen tight clothing, braces, straps or belts, in order to reduce constriction at the neck, chest and waist.
  • Insulate the casualty from cold, both above and below.  Contact the emergency service.
  • Check and record breathing, pulse and level of response.  Be prepared to resuscitate the casualty if necessary.