The main cause of illness is a poor digestive system. If the digestive fire (agni) does not burn strongly enough, foods do not get digested. If food is not digested, nutrients cannot be absorbed. When foods do not get digested, they sit and accumulate in the colon, becoming a breeding ground for yeast infections, toxins, gas, and constipation. Undi- gested foods are called áma. Áma is the root cause of most problems in the body, resulting from ex- cess Váyu or Kapha (or both). If the agni burns too much, heat and acid build up in the system, creating Pitta problems.
Digestion begins in the mouth and stomach as saliva acts upon the food to digests it. Práòa Váyu moves the food from the mouth to the stomach (ámáßhaya). Once in the stomach the food takes on a predominantly sweet (madhura) taste. Food
mixes with the digestive enzymes (Pachaka Pitta). Samána Váyu moves the food to the duodenum (grahaní) where digestion continues due to the digestive fire or agni (koßóhágni), assuming a pun- gent taste. The liver and pancreas are involved in the digestive process.
Finally, the large intestine (Váyu) absorbs the air and ether elements. Here, undigested foods be- come feces, and water is absorbed, transferred, and eliminated through the urine.
Properly digested food creates nutritional es- sence, chyle, or plasma (rasa). Improperly digested food becomes undigested food toxins (áma) that are the cause of most diseases. Earth foods build protein bulk, such as muscles. Watery foods build vital fluids and fat. Fiery foods build enzymes and hemoglobin. Air foods build bone and nerve plex- uses, and ether foods build the mind.
The health of the immune system determines whether diseases are warded off. Áyurveda notes that there is a sap-like material called ojas (per- haps analogous to pineal gland secretion) that coats the immune system and protects it from disease. If the agni fire is too low or too high, this life sap will be diminished. Just like the tree that creates a sap over the bruise in the bark to protect and heal the bruise, our life sap (ojas) protects and heals us from illness.
Too much dryness or too much heat and fire eats away the life sap. A weak immune system is
the cause of all illness, from colds to multiple scle- rosis to AIDS. To heal the immune system, one needs adequate rest and pure (sattwic) foods and herbs that specifically rebuild the ojas (life sap). Examples include blanched almonds or tahini, and ojas building herbs like ¤hatávarí and a¤hwagandhá, respectively.
So, we have seen that by knowing the constitu- tion and elemental cause of one’s illness
(vik^iti), by knowing which tissue layers (dhátus), systems, and organs are governed by which doßha, and by knowing how to balance the agni fire and build the ojas, Áyurveda offers an individualized, simple, gentle, and effective form of healing.
All diseases can be caused by any of the hu- mors, depending on which sites they relocate to, so the patient is examined completely, using all possible methods. Since disease development (pathogenesis) is the same for all doßhas, only the humors, stages, sites, and directional movement of the humors are examined. Humors have to re- turn to their origin sites to be eliminated.
Áyurveda emphasizes promoting health, pre- venting disease, and enhancing longevity (rejuve- nation or age reversal). By using rasáyana-(reju- venation) promoting herbs and diet, good conduct, daily routine, and seasonal living longevity is developed.