Watch out for this type of person. The whiner, malcontent, sickly type, etc. Almost all of them are textbook narcissists, constantly on the make looking to guilt trip others into doing shit for them. There is no winning with these people, no "one good turn deserves another" or anything like that. They will always be on the receiving end of favors and they never give up, you can never relax around them without suffering the consequences because of their massive and unreasonable sense of entitlement.
Heed this warning, this kind of person is easy to sniff out once you're aware of what to look out for and if you aren't on the lookout they'll get you like some kind of predatory leech because their persistence.