Certain things are meant to be mixed. Strawberries and dark chocolate. Gin and tonic. But for pain relievers, paring down is better than pairing up, because it's easy to get far too much of a good thing. For instance, if you take a pill for sinus congestion on top of something else for head pain, you could cause stomach pain, or worse.

Your rule should be to never take two or more different kinds of over-the-counter (OTC) pain medications together unless your healthcare provider gives the go-ahead. Why? If you're taking NSAIDs -- pain relievers other than acetaminophen, otherwise known as nonsteroidal anti-inflammatory drugs -- popping different types at the same time (say, ibuprofen and naproxen) can dramatically increase your risk of stomach ulceration. Exception: Two types of the same medication may be prescribed by your doc -- maybe a pill and a patch of ibuprofen -- but that's under his or her supervision.

Also, layering ibuprofen with aspirin causes them to fight in your arteries, so you don't get their vascular protective effects and may get too much of a negative stomach effect.

Another rule smart patients live by: Don't take more than the label recommends. The FDA expects you to take OTC meds with common sense, not eat them like candy (we expect that, too). In one survey, more than a quarter of users took more than the recommended dose, and 60% said they didn't know there could be consequences. If you're tempted to take extra to squelch the pain, you need to see your doc for a healthier strategy.