Frankly this is a question that needs to be answered by a financial expert. Most of what I have heard is through conversations trying to get a client pre-approved. It is my understanding that you take less of a credit hit from medical bills than other types of bad debt....there are a lot of non-profit consumer credit services that can answer those questions for you. These companies will for no charge help you to arrange payments, to pay off ,or settle credit issues. There really are some tremendous avenues (FREE) to get your credit in good shape !
If your are thinking about getting a mortgage it is very important to get pre-qualified in advance so you don't fall in love with a property you can't afford. You can start with a loan officer at your bank or contact a Realtor in the area you are looking, we all have referrals for good loan officers.