The word gets used for being upset, and that is not what this page is about. Medical shock is the circulation failing to deliver enough oxygen to the organs, and it kills people who are still awake and talking.
It is the common final pathway of most serious injury and illness in this app: heavy bleeding, severe burns, anaphylaxis, sepsis, severe dehydration, a heart attack, a major fracture.
What shock actually means
Blood needs to be pumped, and there needs to be enough of it, and the vessels need to hold the right tone. Break any of those three and the organs stop receiving oxygen.
The body compensates hard at first, and that compensation is what you are looking for:
- It speeds the heart up, to move less blood more often.
- It shuts down the skin and the gut, to keep blood for the brain and heart. That is why the skin goes pale, cold and clammy while the person feels awful.
- It breathes faster, to load what blood there is with more oxygen.
Compensation works until it does not, and then it fails suddenly. A person can look reasonable, with a normal blood pressure, right up to the point of collapse. That is the trap.
Recognising it
Restlessness and anxiety come before drowsiness, and are easy to mistake for the person being difficult or panicky. An injured person who is agitated and cannot settle is often becoming shocked, and treating that as emotional rather than physiological is a documented way to miss it.
Capillary refill is a useful bedside check. Press a fingernail or the skin of the chest for five seconds and release. Colour should return within about two seconds. Longer suggests poor perfusion.
What to do
Raising the legs uses gravity to return blood from the limbs to the core, which is the same reasoning as the anaphylaxis page and the opposite of the mistake described there.
Warmth matters more than people expect. A shocked person loses heat fast because their circulation has shut down the skin, and becoming cold makes shock significantly worse and impairs clotting. Cover them, including from below, since the ground takes heat quickly. Do not overheat them with hot water bottles or direct heat, which draws blood back to the skin and away from the organs. Insulate rather than warm.
Do not raise the legs if there is a suspected spinal injury, a fractured pelvis or leg, or if it causes pain. Lie them flat instead.
If they are unconscious but breathing, put them in the recovery position.
The fluids question, answered honestly
Treating the cause
Shock is a symptom. Managing it without addressing what is causing it achieves very little.
| Cause | The actual treatment |
|---|---|
| Bleeding | Direct pressure, elevation, tourniquet if trained and catastrophic. See wound care |
| Anaphylaxis | Adrenaline, immediately. See anaphylaxis |
| Severe dehydration | Oral rehydration, small and often |
| Burns | Cool the burn, keep the person warm, push fluids. See burns |
| Sepsis | Antibiotics and hospital. See recognising sepsis |
| Heart attack | 999, aspirin 300 mg chewed if not allergic, rest, reassurance |
| Major fracture | Splint it, which reduces bleeding into the tissues. See splinting |
| Heat | Cool aggressively. See heat illness |
| Cold | Rewarm the torso. See hypothermia |
Bleeding you cannot see is the one to keep in mind. A closed femoral fracture, a pelvic fracture or abdominal bleeding can lose enormous volumes internally with nothing visible on the outside. Someone who is shocked with no obvious blood loss after a significant impact is bleeding somewhere you cannot see, and that is a surgical problem.
Why it hides
Three reasons people miss it, worth knowing because each one is avoidable.
Compensation masks it. Blood pressure holds up until it suddenly does not. Do not be reassured by someone seeming stable, especially a young fit adult, who compensates best and crashes hardest.
The person may deny it. Adrenaline and the desire not to make a fuss keep people upright and talking well past the point where they should be lying down. Somebody insisting they are fine while grey and clammy is showing you the signs, not the truth.
It is attributed to emotion. Pale, shaky, nauseated and anxious after a frightening event gets called "just shaken up". Sometimes it is. Sometimes it is the circulation failing, and the two look identical in the first minutes.
The cheap safe response to all three is the same: lie them down, raise the legs, keep them warm, and watch. It costs nothing, it does no harm to someone who was merely startled, and it is the correct treatment if they were not.