Derived from philosophical theories propounded in India over 2,000 years ago, the principles of Ayurvedic Medicine have never been substantiated by contemporary medical science--and no medical conditions have been proven to respond to Ayurvedic treatments. Certain Ayurvedic exercises, such as the meditation and gentle stretching exercises of yoga, afford people relief from tension and stress. However, any impact these exercises have on chronic conditions such as high blood pressure appears to be momentary, and can't be considered a lasting remedy.

Ayurvedic practitioners generally begin by taking a comprehensive personal and medical history to determine your physical and spiritual "type," and then prescribe and treat accordingly. Expect detailed questions about your emotional temperament, skin type, food preferences, and other quirks. The practitioner is also likely to examine your tongue and spend a significant amount of time taking your pulse. (In the Ayurvedic view of medicine, the pulse is a critical diagnostic tool, revealing imbalances in the three basic principles at work in the body.)

Much like traditional Oriental medicine, the Ayurvedic system aims not just to treat diseases, but to maintain and balance the energy and health of both mind and body. It emphasizes avoidance of stress and a moderate, balanced lifestyle. The version of Ayurvedic medicine commercialized in the United States is a relatively recent "reconstruction" of ancient Indian medical practices, refined and tailored to meet Western expectations and tastes. In India itself, Western-style medicine is replacing many of the older practices.

The frequency and duration of Ayurvedic treatments vary widely. Many aspects of Ayurvedic practice, such as dietary choices and yoga, can be self-administered on a regular basis or as needed. Typical measures may include massage with warm sesame oil; avoidance of certain types of foods (based on flavor, not nutritional content) and emphasis on others; breathing exercises, such as breathing alternately through one nostril and then the other; and herbal saunas or enemas to "detoxify" the body. A comprehensive program of treatments, called panchakarma, aims at overall "purification" and rejuvenation, and may be offered at some Ayurvedic clinics, centers, or spas.

According to Ayurveda, there are three doshas, or basic metabolic types: kapha, pitta, and vata. Each dosha is rooted in specific organs of the body and associated with two of Ayurveda's elements (earth, water, fire, air, and space, or "ether"). Combinations of these doshas in various proportions are said to yield a total of 10 body types which determine each individual's physical and emotional makeup.

The Ayurvedic practitioner's job is to identify the individual's "tridosha," a unique combination of the three doshas, and prescribe dietary patterns, exercises, lifestyle changes, and therapies designed to bring the tridosha into balance. People described as predominantly "vata" are thought to be thin, quick, and energetic; "pitta" types are considered competitive and hot-tempered; "kapha" types are regarded as calm and stolid. Each type is considered prone to characteristic ailments (for example, "pitta" types are thought to be more vulnerable to ulcers, inflammation, or rashes).

Identification of one's tridosha determines an array of recommendations, ranging from dietary choices to the best types of exercise. Ayurvedic dietary advice is based on food's flavor rather than its nutritional content as defined by Western science. Increasing your intake of sweet, sour, and salty foods, for instance, is said to balance "vata." Herbal prescriptions are drawn from a vast selection of traditional Indian remedies, most of them unfamiliar to Westerners. (Don't make assumptions. Even familiar herbs may be used for different purposes than those documented by Western medical research.) Attempts to "purify" the body through excretion are also stressed, including herbal enemas and steam treatments. (Induced vomiting, a purgative technique used in Indian Ayurvedic practice, has--not surprisingly--been avoided by American practitioners.)

In any event, it's wise to be especially wary of the purgative treatments sometimes recommended by Ayurvedic practitioners. Overuse of laxatives and enemas can lead to serious chemical imbalances within the body. Laxatives, in particular, should never be taken in the presence of abdominal pain, nausea, or vomiting without first consulting a regular doctor.

Likewise, if you must follow dietary restrictions in order to manage a serious disorder such as diabetes or heart disease, it's advisable to consult a physician or registered dietitian before adopting an Ayurvedic diet plan. Because Ayurvedic recommendations are based mainly on the flavor of food, they may be at odds with the body's requirements as understood by contemporary medical science.