Ginger, the underground stem, or rhizome, of the plant Zingiber officinale has been used as a medicine in Asian, Indian, and Arabic herbal traditions since ancient times. In China, for example, ginger has been used to aid digestion and treat stomach upset, diarrhea, and nausea for more than 2,000 years. Since ancient times, ginger has also been used to help treat arthritis, colic, diarrhea, and heart conditions. In addition to these medicinal uses, ginger continues to be valued around the world as an important cooking spice and is believed to help the common cold, flu-like symptoms, headaches, and even painful menstual periods.