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Quick guide · 3 min read

Heart Attack: Recognise It and Act

Central, crushing chest pain that may spread to the arm, neck or jaw, with sweating, nausea or breathlessness: treat it as a heart attack. Call 999, sit them down in the W position, and give a single 300mg aspirin to chew slowly if they are not allergic. Be ready to start CPR.

Spot it

  • Persistent, vice-like pain in the centre of the chest
  • Pain spreading to the left arm, both arms, neck, jaw or back
  • Pale, grey, sweaty skin; nausea; breathlessness; a sense of impending doom
  • It can be milder, especially in women, older people and diabetics: discomfort, indigestion-like pain, unusual tiredness

What to do

  1. 1

    Call 999 immediately.

    Do not drive them yourself and do not wait to be sure. Minutes of heart muscle die while you hesitate.

  2. 2

    Sit them down in the W position.

    On the floor, back supported against a wall or furniture, knees bent. It eases the heart's workload and prevents injury if they collapse.

  3. 3

    Aspirin: one 300mg tablet, chewed slowly.

    Only if they are not allergic, not under 16, and can swallow safely. Chewing gets it working faster; it slows the clot doing the damage.

  4. 4

    Stay, reassure, and be ready for CPR.

    Loosen tight clothing. If they become unresponsive and stop breathing normally, start CPR at once and send for a defibrillator.

Cardiac arrest is different

A heart attack is a blocked pipe: the person is usually conscious and in pain. A cardiac arrest is the pump stopping: they collapse, lose consciousness and stop breathing normally. A heart attack can trigger a cardiac arrest, which is why you stay and stay ready. Arrest means CPR and an AED, immediately.

Do

  • Call 999 at the first suspicion
  • Sit them in the W position: floor, back supported, knees bent
  • Give 300mg aspirin to chew, if safe to do so

Don't

  • Do not let them walk around or fetch things
  • Do not give aspirin to under-16s or anyone allergic to it
  • Do not leave them alone while you wait

Common questions

What does the aspirin do in a heart attack?

A single 300mg aspirin, chewed slowly, thins the blood and slows the growth of the clot blocking the coronary artery. Give it only if the person is over 16, not allergic and able to swallow safely, and call 999 first.

What is the difference between a heart attack and a cardiac arrest?

A heart attack is a circulation problem: a blocked artery starving heart muscle, with the person usually conscious. A cardiac arrest is an electrical problem: the heart stops pumping, the person collapses and stops breathing normally, and needs CPR and a defibrillator immediately.

Related skills

CPR & DefibrillatorShock & FaintingPrimary Survey · DRABC

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First Aid Guru guides support learning and refreshing your knowledge. They are not a substitute for regulated, hands-on first aid training or for professional medical advice. In an emergency call 999 (UK) and follow the call handler's instructions.