First aid

16 April 2008


Shock is a life-threatening condition which occurs when the blood flow is so low that oxygenated blood does not reach vital organs, such as the brain and heart.


  • Shock is when blood pressure drops suddenly and drastically, which may lead to tissue damage and death.
  • Any condition that reduces blood flow to the cells e.g. severe bleeding, dehydration, heart failure or severe allergic reaction, can cause shock.
  • Early symptoms of shock may include confusion, restlessness and anxiety.
  • Call an ambulance immediately if you suspect someone is going into shock.
  • Elevate the person’s legs if they have no spinal injury, keep them warm and calm, and don’t give them anything to eat or drink.

What is shock?
In ordinary language, we use the term “in shock” for when someone has experienced a frightening event or has heard emotionally upsetting news.

But when doctors say someone has “gone into shock”, they mean that the person’s blood pressure has dropped suddenly and drastically. When this happens, the cells don't receive enough blood – and therefore, not enough oxygen. As a result, the cells can become quickly damaged, and the vital organs can’t function normally. Someone in shock requires immediate treatment, or they may die.

Note: blood pressure can drop from an emotional shock, and may cause fainting. This is called ‘psychogenic shock’ and is not true shock, which is more severe.

What causes shock?
Shock can be caused by any condition that reduces blood flow to the cells. There are different types of shock, with different causes:

  • Shock due to low blood volume. The volume of blood in the body may be low, because of severe bleeding or dehydration. Rapid blood loss may occur because of external bleeding e.g. from an accident; or internal bleeding e.g. from a burst blood vessel. Dehydration may result from fluid loss e.g. through severe diarrhoea or not drinking enough liquid.
  • Shock due to inadequate pumping action of the heart. This may occur after a heart attack, heart failure, or certain other heart problems.
  • Shock due to extreme dilation of the blood vessels. This may result from head or spinal injury, liver failure, poisoning or an overdose of drugs that dilate the blood vessels. It may also result from a severe allergic reaction, in which case it is called anaphylactic shock. Shock resulting from a serious bacterial infection is called septic shock. Toxic shock syndrome is a type of septic shock.

Symptoms of shock
In the early stages of shock, symptoms may not be obvious, and may differ somewhat depending on the cause and type of shock. As the condition progresses, symptoms become more noticeable. Sometimes the only early signs are confusion, restlessness or anxiety.

Sometimes, conversely, the person may appear lethargic and sleepy. The skin may be cold, sweaty and pale. When shock results from blood vessel dilation, however, the skin may be warm and flushed at first, and cold, clammy skin and lethargy only occur later on. Usually, breathing is rapid and shallow, and the pulse is weak and rapid. Urine flow is very reduced. The person feels dizzy or faint, and will eventually become unconscious.

First aid for shock

  • Call an ambulance immediately if you suspect someone is going into shock.

  • Check the ABC's: airway, breathing, circulation. If necessary, begin rescue breathing and CPR. Any external bleeding should be stopped, if possible.

  • If the person is vomiting or unconscious, place him in the recovery position.

  • If a person is conscious and you are certain there is no spinal injury, he should lie on his back with his legs elevated about 30 cm to increase blood flow to the heart.

  • Keep the person warm by covering him with a blanket, and loosen tight-fitting clothing.

  • Do not give any fluids or food. This is because of the risk of vomiting; also, the stomach should be empty in case as well an anaesthetic is required at hospital. If the person is thirsty, you may moisten the lips with a little water. If the person requires fluid the ambulance personnel can put up a drip.

  • Stay with him until help arrives and monitor and record his breathing, pulse and consciousness every five minutes. Be reassuring.
Reviewed by Barry Milner, Instructor, Blue Star Academy of First Aid; BLS National Faculty and First Aid Representative (Resuscitation Council of Southern Africa)

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