While there are difficulties in awarding damages for pain and suffering, it is important that such damages be available as a way of compensating successful plaintiffs. The reason for this is that not all injuries suffered by a plaintiff can be compensated for in other ways.
For example, let us say that a plaintiff has been wrongly blinded through the actions of the defendant. The defendant is made to pay for loss of income due to the blindness. However, the loss of income (if any) may not be the most important impact of the defendant’s wrongful actions. Let us imagine that the plaintiff has children he will never see again. Let us imagine that his hobbies were painting and watching sports. Let us further imagine that there was great physical pain involved. None of these things are compensated for simply by awarding the plaintiff damages for lost wages and medical expenses.
One of the purposes of awarding damages is to allow the plaintiff to be made whole for all of the injuries he has suffered. Without the possibility of damages for pain and suffering, it would be exceedingly hard to accomplish this goal.