Between Delhi's crushing crowds and Mumbai's glamour and glitz -- not to mention the countless temples and castles -- there's no shortage of exotic attractions for travelers in India. But a growing number of visitors are spending less time at the Taj Mahal [Images], and are instead seeking out the medical and spiritual benefits of traditional Ayurvedic treatment at the high-end spas popping up all over India.

Ayurveda, which literally means "knowledge of life," originated in South India more than 5,000 years ago and is considered a longevity science in the subcontinent. In simple (and possibly overly brief) terms, Ayurveda says the body consists of three main aspects: vata, pitta and kapha. These can come out of alignment due to pollution, stress, disease and even just the strain of everyday life. The goal of an Ayurvedic practitioner, then, is to rebalance to this system -- thereby bringing the subject back to his or her "true self."

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While the Indian government doesn't have specific figures for the number of people who come to the country specifically for Ayurveda, a recent McKinsey Report for the Confederation of Indian Industry says that medical tourism from the West could grow at an estimated 30 percent a year. (This includes visitors who come for traditional medical procedures, including surgery. Click here for Forbes Traveler's report on Medical Tourism.) According to the study, this could conceivably add $1 billion to the Indian tourism industry by 2012.

Most luxury hotels in India offer some form of Ayurvedic treatment, usually focusing on prescribed massages using essential oils -- the same types of treatments you can get in the US. But true Ayurvedic practice in India is more holistic.

"People equate Ayurveda simply with massage, but that isn't correct," says Dr Komal Shah-Kapoor, Director of Research at SpaFinder. "In the US, massage and parts of Ayurveda are taken and made into an enjoyable spa treatment, but that's a little different from the way Ayurveda takes place in India. It's not just working on one part of the body; it's working on the whole body."

Traditional Ayurvedic practitioners combine massage with medicinal herb treatments, restricted diet, meditation and yoga. "When they treat an illness, it isn't just about treating the illness," says Dr Shah-Kapoor. "They suggest nutritional guidelines and they suggest lifestyle changes. Everything that they do basically taps into natural resources and helps you to remove the cause of that illness." According to Shah-Kapoor, 80 percent of Indians follow some form of Ayurveda.

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Since Ayurveda originated in Southwest India, in the lush forests and swampland of what is now the state of Kerala [Images] -- the native home to the herbs and oils used in the treatment -- that's where many of the best known resorts, or shalas, are located.

The Divya Spa at the Leela Kovalam Beach Resort sits atop cliffs overlooking the Arabian Sea, and offers such treatments as Shirodhara (opening of the third eye), a process of pouring warm herbal being in a steady stream onto the forehead. Aside from the spiritual effects, the Shirodhara is said to enhance blood flow to the brain and "synchronize brain waves," resulting in improved memory, healthier hair and reduced tension.

In Calicut, the Taj Ayurveda Center offers a range of therapies that include snana, which is a bath with herbal powders that can last as long as three hours. In a dhara treatment, medicated oil, milk and buttermilk are poured on the head and body to alleviate fatigue, insomnia and a host of other ailments.

For Ashish Sanghrajka, vice president of sales and partner relations for Big Five Tourism expeditions, Ayurveda can lead to better health -- and even better looks.

"Ayurveda can be used to take wrinkles away from the face," he says, and "people have used Ayurveda to try and treat diabetes; they've used Ayurveda to try and cure cancer... It helps people to feel less stressed out, but it also helps them to feel younger. And it's not through medicine -- just through diet, and yoga and body movements, and general massages." For Sanghrajka, the key is increasing blood flow, muscle expansion and flexibility.

Indians undergoing Ayurvedic treatments will often go to resorts for two or three weeks or more, making the pilgrimage for healing and detox programs that include fixed diets, daily regiments of yoga and meditation, and medicinal spa treatments prescribed by a doctor. For more hardcore Ayurvedic practitioners (with more time to spare), centers such as the Agastya Ayurveda Garden Resort offer a 62-day circuit that starts with massages and steam treatments, then progresses to "therapeutic vomiting," enemas and sometimes even blood-letting.

For a deluxe Ayurvedic experience -- without the blood-letting -- The Coconut Lagoon in Kumarakom is a safe bet. The resort sits upon Vembanad Lake and can only be accessed via boat along Kerala's renowned backwaters. They offer a full slate of Ayurveda paired with excursions to nearby cultural attractions.

Ayurvedic practitioners generally say that the muggy summer monsoon season is the best time to undergo treatment because heavy rains are effective in taking dust out of the air and sweating is thought to be purifying. But Southern India can be brutally hot in the summer. If you're not up for the heat, one of the north's top Ayurvedic destinations is the 21,000-square-foot Ananda Spa, located in the Himalayan foothills near Rishikesh, the former home of the Maharaja of Tehri-Garhwal. Many of the spa's 79 body and beauty treatments combine Ayurvedic principles and yoga with other Western practices.

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