If you're in a car accident or have a bad slip and fall while shopping, and the accident aggravates a pre-existing condition, do you still have the right to sue?
Absolutely. There's a provision in the law known sometimes as the "Eggshell Doctrine" or the "eggshell skull rule," that addresses your situation. In essence, it says that if your condition was stable and you had no reason to believe that was about to change, you're still entitled to damages for an injury caused by someone else's negligence—even if your health and well-being was as fragile as an egg.
This doctrine comes into play quite often when pursuing damages for injuries done to victims who are elderly or those who have disorders that make them especially susceptible to harm for some reason.
For example, imagine that you have degenerative arthritis. You have been managing your condition just fine with occasional pain medication and physical therapy. Now, imagine that you slipped on the newly waxed floor of a store because no one bothered to block off the area until the floor dried, put up warning signs or throw down rubber-backed mats to make it safe for shoppers.
Someone without your type of arthritis might end up with a few bruises and a sore back that requires a little chiropractic care. Because of your degenerative arthritis, however, you end up in the hospital with collapsed vertebrae in your neck and eventually need a cervical fusion with several titanium pins to stabilize you against further damage. You also develop nerve pain in your dominate hand and have limited range of motion that now affects your ability to drive, lift, carry or do a number of other things.
Both you and the person who only suffered a few minor injuries and some out-of-pocket medical expenses both have a right to compensation. The compensation you would deserve would be significantly higher, because your loses would be significantly worse.
The defense will likely want to argue that your condition was inevitable, but if you'd never been told that you needed a cervical fusion and your condition was considered stable prior to the accident, they may have a hard time convincing a jury to agree.
Never assume that a pre-existing condition prevents you from filing a claim for compensation due to a serious accident and personal injury. An attorney can provide advice instead.
Source: Columbia Center For Occupational & Forensic Psychi, "Eggshell Skull," David J Fischer, MD Medical Director, accessed Jan. 20, 2017