Although Indiana allows damages to be awarded for pre-existing conditions that get worse due to an accident, juries tend to award lower amounts than injuries caused by an accident.
Auto insurance companies and their defense lawyers know this trick. So, they search and search for prior complaints of pain or injury to the same parts of the body you've injured in this claim or accident. They might send loads of written questions called interrogatories. The insurance companies might require you to sign medical authorizations and list all prior doctors, hospitalizations and injuries you have ever suffered.
Then the auto insurance companies and their defense lawyers will send those authorizations to your prior doctors and search for similar complaints to those you are currently experiencing.
Remember, only your doctor can testify whether an injury or pain was caused by the accident or incident. Your complaints will be noted by the doctor in his records (hopefully), but it takes medical testimony to establish this fact under Indiana law for a jury to assess damages.
Do not lose hope. Indiana juries will be instructed by Judges that they are to consider an injury that got worse and compensate accordingly.