We've all had that throbbing kind of pain (or probably, most of us have). But what IS the throb? What is that feeling? Most of us (including scientists) think it's the throb of your heartbeat, felt through sensitized nerves in response to the pain. But...it's not. What it is? ...we don't know. Head over to Neurotic Physiology to check it out.
The views expressed are those of the author(s) and are not necessarily those of Scientific American.