To elaborate upon
Webster 1913's smallish entry: In
medical terms, shock means a severe state of too-low
blood pressure. This can be
life-threatening, because blood supplies vital chemicals (most notably
oxygen) to every
organ in our body, and if blood pressure is too low, it means that blood can't circulate properly and organs (most notably the
brain) may end up starved of resources.
There are three main forms of shock:
- lack-of-volume shock: induced by a lack of blood, usually resulting from some kind of injury through which
blood is lost. The bleeding may be internal, in which case the cause of shock is non-obvious.
- anaphylactic shock: cause by strong allergies, e.g. against bee poison. The allergic reaction can cause all the blood vessels to become wider than they should be, which also sends blood pressure tumbling. This can also happen as a result of sheer pain, compounding a lack-of-volume shock, or replacing it with some injuries (such as broken bones) where blood loss is not serious enough to cause one.
- cardiogenic shock: occurs when a malfunction of some sort weakens the heart to the point where it can't provide the necessary blood pressure.
Shock symptoms include
dizziness,
sickness
and general
weakness, leading to
unconsciousness if not treated. A carciogenic shock is distinguishable from the other types by blood vessels at the throat swelling and standing out visibly. This is important becuase a cardiogenic shock
must not be treated like the other types!
Shock countermeasures: usually, the best and easiest thing to do is to let the patient lie down and place his or her feet in an elevated position ("shock position") so that blood from the legs becomes available to the more vital parts of the body and supplying the brain becomes an easier job for the heart (no height difference). In case of a lack-of-volume shock, the lost blood volume should be added throug an infusion. In case of an anaphylactic shock, the patient must be given anti-allergic medicine as quickly as possible.
However, in case of a cardiogenic shock, the shock position only compounds the problem, as it places additional strain on the heart! In that case, the patient should be kept sitting.
In all cases, not only related to shock, an important aspect is psychology: keep the patient comfortable and non-frightened as far as possible, ensure him or her that everything humanly possible is being done, that help will arrive soon, etc. Rule No. 1 of first aid is: Keep talking to the patient!