I tend to resist taking painkillers unless it's absolutely necessary. Problem is, I'm not all that good at telling if it's absolutely necessary. Period pain? Yes, it doesn't go away by itself. If I leave it I'll be in screaming agony for three days. Back pain? Well, sometimes just lying down clears it. Sometimes a hot shower's enough.
Now it is 10 hours after my alarm went off the first time, and my back still hurts. I have taken painkillers, am sitting in my "special" orthopedic, back-supporting chair, and my back still hurts. Gods damn it.