Shock – Symptoms and First Aid Advice

Shock is a life-threatening condition in which the circulatory system fails to deliver enough oxygen-carrying blood to the body’s tissues. It is most often caused by a sudden loss of blood or other body fluids, but anything that stops the heart pumping effectively, or that makes the blood vessels widen suddenly, can bring it on. The tissue cells throughout the body are starved of oxygen and, without treatment, this leads to organ failure and death.

Shock has several possible causes (for example, traumatic injury), but it’s often associated with severe bleeding.

Last reviewed: September 2026 — checked against Resuscitation Council UK Guidelines 2025.

If you would like to further your first aid skills we also offer a range of first aid courses.

---

What Causes Shock?

In first aid, “shock” means circulatory failure. It is not the same as the emotional shock people describe after a frightening experience, and it is far more serious.

The causes fall into a few groups:

• Severe blood loss, either visible or bleeding internally – the cause a first aider is most likely to meet.
• Loss of other body fluids, through serious burns, severe vomiting or diarrhoea, or heat exhaustion.
• A heart that cannot pump properly, for example during a heart attack or heart failure.
• A severe allergic reaction (anaphylaxis), which makes blood vessels widen and leak.
• Severe infection (sepsis).
• A spinal cord injury, which can stop the body controlling the width of its blood vessels.

Whatever the cause, the effect is the same: too little oxygen reaching the organs. At first the body compensates by speeding the heart up and shutting down the circulation to the skin, which is why someone in shock looks pale and clammy while their pulse races. Once that compensation fails, the casualty can deteriorate very quickly.

Signs and symptoms include:

The signs tend to appear in this order as shock deepens:

• pale, cold, clammy skin – with grey or blue-tinged lips; on brown or black skin this is often easiest to see on the palms, the soles of the feet or inside the lips;
• sweating;
• a fast heartbeat, which becomes weak and hard to find as shock worsens;
• fast, shallow breathing;
• weakness and dizziness;
• feeling sick, or vomiting;
• thirst;
• restlessness, anxiety or unusual aggression;
• yawning or gasping for air;
• confusion and a falling level of response;
• unconsciousness or unresponsiveness – a late and very serious sign.

Blood pressure does fall in shock, but a first aider has no way of measuring it. Judge the casualty on how they look, how they are breathing, and above all on whether their level of response is changing.
Serious burns are an important cause, because of the volume of fluid lost through the damaged skin. Being frightened or upset is not the same thing as clinical shock – although fear and pain can make genuine shock worse.

---

What should you do if you see someone who is in shock?

Shock is a medical emergency, so the ambulance call comes first – not after you have treated the casualty.

1. Dial 999 or 112 straight away. If the casualty is unresponsive, make the call before you check their breathing: under Resuscitation Council UK Guidelines 2025 you call 999 for any unresponsive person, and you no longer need to confirm that their breathing is abnormal first. If they are still responsive but you suspect shock, call anyway – shock is life-threatening and will not improve on its own. Tell the call handler you think the casualty is in shock and what you think caused it, and put your phone on speaker so both hands stay free.
2. Treat the cause, if you can see one. Control life-threatening bleeding with firm direct pressure on the wound. If you suspect a severe allergic reaction, use an adrenaline auto-injector immediately. Deal with anything else you found in the primary survey.
3. Lay the casualty down and raise their legs, supporting them on a chair or a pile of coats, to help blood return to the vital organs. Do not raise the legs if you suspect a spinal injury or a fracture in the leg, or if it causes pain.
4. Loosen any tight clothing around the neck, chest and waist.
5. Keep them warm. Cover them with a coat or blanket and insulate them from a cold floor. Do not use a hot water bottle or any other direct heat, which draws blood to the skin and away from the organs that need it.
6. Reassure them and keep them as still and calm as you can, because fear and pain raise the body’s demand for oxygen and make shock worse.
7. Do not give them anything to eat or drink. If they complain of thirst, moisten their lips with a little water.
8. Monitor and write down their level of response, breathing and pulse while you wait for the ambulance, and be ready to start CPR if they stop breathing normally.

What Not to Do

• Do not give the casualty anything to eat, drink or smoke. They may need an anaesthetic in hospital, and drinking can cause vomiting.
• Do not use a hot water bottle, heat pad or fire to warm them.
• Do not let them get up and move around, even if they say they feel better.
• Do not raise the legs if you suspect a spinal injury or a broken leg.
• Do not leave them on their own, except to go and call for help if there is no other way.

If the Casualty Becomes Unresponsive

You will already have called 999. Open the airway by tilting the head back and lifting the chin, then spend no more than 10 seconds checking for normal breathing. Do not check for a pulse – lay rescuers are no longer taught to, because it wastes time and is unreliable.

If they are breathing normally, place them in the recovery position and keep watching them until the ambulance arrives.

If they are not breathing normally – and occasional gasps do not count as normal breathing – start CPR immediately: 30 chest compressions in the centre of the chest, 5-6 cm deep at a rate of 100-120 per minute, followed by 2 rescue breaths. If you have not been trained to give rescue breaths, or you are unwilling to give them, give continuous chest compressions instead – hands-only CPR. Send someone for the nearest defibrillator and use it as soon as it arrives; anyone can use an AED and no training is needed.

Shock Caused by a Severe Allergic Reaction

Anaphylaxis is a severe allergic reaction that can cause shock within minutes of contact with a food, a medicine or an insect sting. It is treated differently from other forms of shock, and NHS advice is to work through these steps:

1. Use an adrenaline auto-injector (such as an EpiPen) straight away if one is available. The instructions are printed on the side of the device.
2. Call 999 and say that you think the person is having an anaphylactic reaction.
3. Lie them down. You can raise their legs. If they are struggling to breathe, raise their shoulders or let them sit up slowly. If they are pregnant, lie them on their left side.
4. If they have been stung, try to remove the sting if it is still in the skin.
5. If their symptoms have not improved after 5 minutes, use a second adrenaline auto-injector.

Do not let them stand or walk at any point, even if they say they feel better.

---

If you or your employees need first aid qualifications, take a look at our range of first aid training courses. Alternatively, get in touch today to find out more.

Related articles

UK Heart and Circulatory Diseases Statistics (2026)Read moreAdapting First Aid for Employees with DisabilitiesRead moreHow to Choose the Right First Aid Kit for Your WorkplaceRead more