Herbal remedies are used as much as, if not more often than, acupuncture to treat energy imbalances and illness. Herbs are often described according to four basic qualities and properties: nature, taste, affinity, and primary action. They are normally recommended in combinations so that they can be customized to each patient. The prescription of herbal remedies takes a TCM practitioner years to master because it requires a deep understanding of medical theory and the complexity of herbs.