It may seem obvious. You have a headache, you reach for acetaminophen. You start feeling menstrual cramps, you take a few ibuprofen. You wake up with stiff, arthritic fingers, you swallow some aspirin or naproxen. 

But are the rules for taking over-the-counter (OTC) pain relievers any different if you’re a cancer patient on active cancer treatment? Are there any circumstances in which you should not take them? 

Read on to...