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Shock

Dr Lynn Thomas, OStJ, BSc, MB.BS, MA, FRCPClinically reviewed: 28/04/2025

Shock - not to be confused with emotional shock – is a life-threatening condition. It happens when the body isn’t getting enough oxygen to the brain and vital organs. Find out what to look for and how to perform first aid.

What is shock?

Shock can be caused by anything that reduces the flow of blood, such as:

  • severe internal or external bleeding

  • heart problems, such as a heart attack or heart failure

  • loss of body fluids from dehydration, diarrhoea, vomiting, or burns

  • severe allergic reactions and overwhelming infection (septic shock)

  • spinal cord injury.

Signs and symptoms

Look for:

  • pale skin, which may be cold and clammy

  • sweating

  • a fast pulse as shock gets worse

  • fast, shallow breathing

  • a weak pulse

  • grey-blue skin, especially inside the lips (with dark skin, look at the palms of the hands and the base of the feet)

  • nausea and possible vomiting

  • restlessness and aggressive behaviour as the brain's oxygen supply decreases

  • yawning and gasping for air

  • the casualty could become unresponsive.

What to do

  1. 1

    First, treat any cause of shock that you can see or that you have identified from the primary survey, such as severe bleeding.

  2. 2

    Then help the casualty to lie down. Raise their legs, supporting them on a chair. This will help to improve the blood supply to their vital organs.

    • If available, lay them down on a rug or blanket to protect them from the cold.

  3. 3

    Call 999 or 112 for emergency help and tell ambulance control you think they are in shock. If possible, explain what you think caused it.

  4. 4

    Loosen any tight clothing around the neck, chest, and waist to make sure it doesn’t constrict their blood flow.

  5. 5

    While waiting for help to arrive, cover them with a coat or blanket to help keep them warm.

    • Remember, fear and pain can make shock worse by increasing the body’s demand for oxygen, so try to reassure the casualty and keep them calm if you can.

  6. 6

    Monitor their level of response.

    • If they become unresponsive at any point, prepare to treat them as an unresponsive casualty.

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