Frequently a worker will have a pre-existing health condition. The pre-existing condition can be the result of numerous causes, including but not limited to the natural aging process, a prior work injury, or an accident unrelated to work.
Sometimes a pre-existing condition will make the worker more susceptible to a work injury. For example, a worker that has had prior shoulder or back surgery might be injured doing a job that would not have hurt a worker who did not have a pre-existing problem. The worker with the pre-existing condition is sometimes called an “eggshell plaintiff” because they are more easily injured than an average person. However, under Iowa work comp law even though a worker might be an eggshell plaintiff, if he gets hurt on the job he is entitled to receive workers’ compensation benefits.
Sometimes a worker may have a pre-existing condition that is completely latent or symptom free and does not cause him any problems. If a worker with such an asymptomatic condition is injured on the job he will generally be entitled to be compensated for the entire resulting disability from the injury even though the final disability is caused by a combination of the pre-existing condition and the work injury.