I had some bad reactions to NSAIDs (asthma attacks & bad headaches). I was never sure if I was having an attack come on and thus took aspirin, or if the aspirin was causing it. Eventually I went to a doctor and it turns out there's a allergy-like sensitivity to these things that some people have.
https://en.wikipedia.org/wiki/NSAID_hypersensitivity_reactio...
NSAIDs-exacerbated respiratory disease
N.E.R.D.
I found out that (scientifically speaking) I am a NERD (or have NERD, whatever)