Hemorrhoids often itch when swollen veins in the anus or rectum trigger inflammation. Inflammation, in turn, stimulates the release of a chemical called histamine that causes itching of the anus ...

“Conventional cold and flu drugs—like dextromethorphan, phenylephrine, pseudoephedrine, and guaifenesin—came onto the market in the 1950s and 60s. They work by affecting ...