The time and duration of a disease, said the ancient sages, depend upon the completeness or partial presence of its causes, the strength or weakness of the individual, and the times of day or night, or even the state after eating. Thus, the meaning of “cause” has been explained, and Vyāsa himself would further instruct on this matter. At the root of all diseases lies the aggravation of the three humors—wind (vāta), bile (pitta), and phlegm (kapha). Various improper behaviors that provoke these humors have already been described, including the threefold improper conjunctions of the humors themselves. Wind is disturbed by excessive use of bitter, pungent, astringent, sour, or dry foods, or by insufficient nourishment. Activities such as running, excitement, staying awake at night, or speaking too loudly also aggravate wind. Overexertion, fear, grief, anxiety, excessive exercise or sexual activity, and eating at the end of long summer days and nights—all these further disturb vāta. Bile is provoked by pungent, salty, sharp, hot, or spicy foods, by anger, by sensations of burning, and especially during autumn, midday, and midnight. Phlegm, on the other hand, increases with foods that are sweet, sour, salty, unctuous, heavy, and cool—those that bring pleasure to the mouth, induce sleep, are hard to digest, and are consumed during the day or before sleep. Forced vomiting after eating, especially when food is not yet digested, and particularly in the morning and early night, also give rise to disorders of phlegm. When these factors combine, a mixed disorder of the humors arises. Eating incompatible, poorly digested, irregular, or mutually antagonistic foods contributes to this. Spoiled wine, impure water, dried vegetables, roots, oil-cakes, rotten meat, putrid, dried, or emaciated fish—consuming such tainted substances disturbs the three humors. Further, corrupted bodily tissues, wind arising from conflict, possession, or agitation, and the intake of corrupted food or excessive phlegm, as well as planetary afflictions at birth, improper practices, indulgence in sinful acts, irregularities during childbirth for women, and improper treatments, all can provoke disease. When the humors, angered by such causes, give rise to illness, one should quickly resort to rejuvenation therapy, for the humors soon become disturbed within the body. At this point, Dhanvantari, the divine physician, spoke: “I shall now explain the origin of fever, so that all fevers may be understood. Fever is the lord of diseases, the embodiment of sin, king of death, devourer, and ender. It arose from the wrath of Rudra, who destroyed Daksha’s sacrifice. This fever, filled with burning and delusion and born of transgression, is fierce and known by many names; it manifests in various forms among all beings. In elephants it is called Pākala, in horses Abhitāpa, in donkeys Alarka, in dogs Kukrura; in clouds it is Indramada, in water Nīlikā, in luminous herbs Jyoti, and in the earth Ūṣara. Symptoms such as nausea, vomiting, cough, stiffness, coldness, and eruptions on the skin and limbs arise from phlegm. In each season, the onset and increase of these symptoms occur as appropriate, and their alleviation is as stated in their causes—by applying their opposites. Loss of appetite, indigestion, stiffness, and lethargy; burning in the heart, improper digestion, drowsiness, fatigue, distension, pain, and inactivity of the humors—these are the signs to be observed. Excessive salivation, nausea, loss of hunger, tastelessness in the mouth, clarity, heat, heaviness of the limbs, and frequent urination are not the signs of digested food nor of malaise, but are symptoms of undigested fever. Conversely, hunger, dryness, lightness of the limbs, and the tenderness of fever, along with the activity of the humors after eight days, are signs that digestion is complete in fever. Whether fever arises from its own symptoms or by contagion, its appearance is marked by headache, fainting, vomiting, burning of the body, dryness of the throat and mouth, loss of taste, pain in the joints, insomnia, confusion, horripilation, yawning, and excessive speech—these come from wind and bile. When fever is caused by phlegm and wind, there is loss of heat, loss of appetite, joint and head pain, spitting, labored breathing, cough, pallor, coldness, stiffness, darkness before the eyes, dizziness, and drowsiness. Fever arising from phlegm and bile is marked by coldness, stiffness, sweating, burning, instability, thirst, cough, the activity of phlegm and bile, confusion, drowsiness, and a coating and bitterness of the mouth. The one who knows all these signs experiences repeated burning; then comes intense sleep, wakefulness during the day, and sleeplessness at night. There may be constant sleep, or none at all; sweating may be profuse, or absent; singing, dancing, laughter, and such activities cease from their natural course. The eyes become tearful, impure, red, sunken, with trembling lashes; pain is felt at the sides of the eyeballs, in the head, joints, and bones, along with dizziness. The ears may ring and ache, or feel extremely cold, or not; the tongue is burnt, rough, heavy, and the joints of the limbs are weak and trembling. There may be spitting of blood and bile, rolling of the head, intense thirst, and the appearance of dark or red patches and circles on the body. Pain in the heart, frequent excretion of waste, scanty or excessive discharges, an oily mouth, loss of strength, hoarseness of voice, and delirious speech may also occur. When the humors are slow to ripen, there is persistent drowsiness and a croaking sound in the throat; when all the humors are disturbed together, it is said to destroy vitality. If the wind is obstructed in the throat and bile is greatly oppressed within, after intercourse or pleasure, it seeks an external path—thus, yellowing of the eyes arises in fever caused by the combined disturbance of humors. If the humors are increased and the digestive fire is lost, and all signs are present, the fever arising from combined humors is incurable; otherwise, it is difficult but not impossible to cure. When fever arises from a combination of humors but bile is separately situated, it causes burning in the skin or abdomen, either before or after. Similarly, when wind and phlegm are involved, there is coldness; burning and similar symptoms are difficult to overcome when both are present. At the beginning of coldness, bile is present; with phlegm, there is oozing and dryness. When bile is pacified, fainting, intoxication, and thirst arise; but at the onset of burning, and in the others, there is drowsiness, lethargy, and vomiting in order. Fever is fourfold in origin: it arises from external injury, from contact, from curses, or from sorcery. Fever from injury is marked by burning and similar symptoms. From exertion, wind commonly vitiates the blood there, causing pain, grief, discoloration, and fever with pain. Fever may also arise from possession by spirits, from medicines, poison, anger, fear, grief, or desire. In such cases, sudden possession or contact may occur, or fever may arise from the smell of medicines; fainting, headache, vomiting, and wasting may result from the scent of certain herbs. Thus, the wise understand the many causes and signs of fever and disease, and the importance of proper conduct, diet, and timely intervention to restore balance and health.