Ephedra is a herbal medicine which was first used by the Chinese more than 5000 years ago. Other names which are commonly used for ephedra include "epitonin", "ma huang", "sida cordifolia" and "sinica". Ephedra relaxes the air passages which can relieve asthma; promotes perspiration which can aid recovery from a cold; and stimulates urination which helps with many urinary problems. The most common type of ephedra in recent years has however been for its properties which boost metabolism and can therefore lead to weight loss. This is usually referred to as ephedra's "thermogenic" or "fat-burning" properties. Ephedra use as a weight-loss supplement has however proved to be dangerous and has resulted in deaths. Most problems arise from individuals taking doses which are too high but complications have also been known to arise in those with heart conditions, as ephedra use raises blood pressure. As a result, the FDA banned the use of ephedra and its derivatives from weight-loss products, and it has since become illegal for this purpose in many other countries. Ephedrine, which is produced from ephedra, may however still be found in medicines used to treat other medical conditions such as asthma and sinusitis.