There is any constant head pain for more than a few hours and the sufferer does not have a history of similar attacks or migraines.
Nosebleeds continue for more than ten to twenty minutes or are particularly severe.
Although herbal medicine is generally quite safe, it can occasionally conflict with orthodox treatments. Note the cautions listed under specific herbs, and if you are on any long-term medication seek advice from your medical practitioner or professional herbalist before taking herbs for any length of time. First-aid use will cause no problems at all in the vast majority of cases, but if you plan to take herbs for longer than a couple of days, it is best to check.
Any medication involves a degree of toxicitya fact of which medieval herbalists were well aware. One must always treat herbsand indeed therapeutic foodswith respect; they are potent medicines. As the great 16th-century herbalist Paracelsus put it: "In all things there is poison, and there is nothing without a poison. It depends only upon the dose whether a poison is a poison or not . . ."