Learning from nature had been the core of Vedas (ancient Indian Culture) and Ayurveda is also not an exception to this. In Vedas, treatments are divided into two - Bheshajam and Aushadham. Bheshajam is prayers, meditation, chanting manthram, homam (sacrifices in fire pit) etc. by which peace of mind, calmness and hope. Aushadham is use of medicines. (The term aushadhi itself means herbal - things available from plants and trees). Hence, there were prayers to Gods and Goddesses for curing illness and general well being along with the use of medicines. Here comes the importance of Lord Dhanwanthari, the God of Ayurveda.

The mythological story goes like this:
To get Amruth (nectar - the medicine for immortality) Devas (heavenly bodies) and Asuras (demons) started crushing Palazhi (milky ocean). From the ocean many things came out - kama dhenu (the holy cow which gives whatever you ask for), Lakshmi (Goddess of wealth), airavatham (the white elephant with 2 pairs of tuskers) and Amruth. Lord Dhanwanthari (a partial incarnation of Lord Vishnu) came out with a pot full of Amruth (nectar).

There are four major Dhanwanthari Temples in Kerala - Thottuva, Nelluvaya, Prayikkara and Maruthorvattom.

Thottuva is a village situated 9 kms North-East of Perumbavoor town and 8 kms East of Kalady on the Southern banks of River Periyar. There is a stream from Periyar that flows towards East (while all other rivers in Kerala are flowing towards West) which is considered sacred.

Myths say, there are many who experienced the magical (medicinal water since it is flowing through the forests) effects of the stream water.

The name of the village is Thottuva because it is situated on the banks ( Vakkath) of this stream ( Thodu). Dasavatharam (10 incarnations of Lord Vishnu) chandanam charthal (applying sandal paste to make a form on the idol of Dhanwanthari) in the Mid-December ( Dhanu 1 - 11).

The oil given to devotees after the abhishekam (washing the idol of Dhanwanthari) is found to be curing various skin diseases.

Every month (Thiruvonam), there used to be a feast ( prasadam oottu) for the devotees. On that day Palpayasam (milk pudding) is offered by some devotees (with pregnancy problems) to conceive child.

Nelluvaya is near Kunnamkulam in Thrissur district. Many medical students (of Ayurveda) and traditional vaidya (Ayurveda physicians) families are the devotees of this temple.

Eye related problems seems to be getting cured after the bhajanam (stay in / near temple for a duration of 21 to 41 days)

Mukkudi (a special combination of herbs) is the most important prasadam (given to devotees). This has a curative power for stomach related problems.

Myth says; there lived a Kuttancheri Moose (a traditional vaidya family member) who used to have less number of people coming to him for treatments than his younger brother. He was worried and went to Nelluvaya for a year bhajanam and later he also started curing all those who came to him.

Prayikkara is another village near Mavelikkara (2 kms in the Mannar route) in the southern parts of Kerala.

Bananas (Kathali type) and Oil are the major offerings.

Maruthorvattom, the name which derived from marunnu oru vattom (means "medicine only once"), is near Cherthalai (Alleppey district). Medam (between April and May) is the month in which the temple festival is celebrating (on Thiruvonam day).

Thalkkari (a curry with some medicinal leaves) is the main offering which the devotees used to get on the full moon days of Karkidakam (July - August), Thulam (October - November) and Kumbham (February - March) months and other days also. This is considered good for stomach related pains.

Myth say; the temple had two owners - Velladu Moose and Chirattamun Moose. After some quarreling Chirattamun Moose took the right hand off from the idol of Dhanwanthari and went to Kottayam. (Now this family is known as Olassa Moose). Mukkudi (a special combination of herbs) is the most important prasadam (given to devotees). This has a curative power for stomach related problems.