In the ancient discourse, the revered Dhanvantari described to Suśruta the various manifestations and causes of swelling and spreading diseases. He began by noting the symptoms that often accompany swelling: itching, pale hair, skin that feels hard and cold, heaviness, oiliness, smoothness, firmness, pain, sleepiness, vomiting, and weak digestion. Sometimes, swelling arises from trauma—such as cuts or wounds—or from exposure to cold or sour winds, or even from the effects of certain plants like bhallātaka and kapikacchu. Swelling can also result from contact with pungent or dry substances, leading to spreading inflammation, intense heat, a reddish appearance, and symptoms that resemble those of aggravated bile. Poison, too, can cause swelling, whether from the bite, scratch, or contact with venomous creatures, or even from non-venomous animals. Furthermore, contamination by impure substances—such as feces, urine, semen—or contact with poisonous plants, winds, or toxic powders may give rise to swelling. This type of swelling is typically soft, mobile, drooping, quick to cause burning and pain, and recent in onset. According to tradition, such swellings may be curable or incurable, depending on their nature. Turning to the topic of spreading diseases like visarpa, Dhanvantari explained their origins. He said, “Listen, O Suśruta. Visarpa arises from injury and from corrupted humors, much like swelling. Its location is usually external, and there, due to fear or exhaustion, it can become more severe; the difficulty of cure depends on which humor is involved. When aggravated by specific irritants, the humors quickly enter the body, either remaining inside or manifesting externally. Excessive thirst, disturbances of natural urges, irregular activity, or a sudden loss of digestive fire can cause the disease to spread outward.” He described how visarpa manifests according to the humor involved. When caused by wind, it is accompanied by symptoms similar to wind-fever: swelling, throbbing, piercing pain, fatigue, and even a sense of exhilaration. When bile is the cause, it spreads rapidly, brings symptoms of bile-fever, and is intensely red. If phlegm is responsible, it is itchy, oily, and resembles phlegm-fever. Sometimes, visarpa arises from the convergence of factors, marked by all signs, accumulating with their own distinctive symptoms, and even disregarding the usual eruptions. Such cases release sweat and bear the characteristics of wounds. Visarpa may be accompanied by fever, vomiting, fainting, diarrhea, thirst, dizziness, rupture of swelling, loss of appetite, darkness, and tastelessness, especially when caused by wind and bile. It can affect all limbs, spreading like glowing embers scattered across the body; wherever the disease reaches, it spreads in that region. As the embers extinguish, the affected areas become black, blue, or red, accumulating as if burned by fire, with eruptions that move swiftly and rapidly. When the spreading follows the vital spots and wind is exceedingly strong, it causes pain in the limbs, takes away consciousness, induces sleep, and produces breathlessness. Hiccups may arise, and the afflicted person may find himself lying on the ground, bed, or seat, struggling and distressed, afflicted with confusion of mind and body, and difficult to awaken from sleep. This is known as fiery spreading. When wind is obstructed by phlegm, it breaks through the phlegm—or sometimes blood—in many ways. In cases where blood is increased, it affects the skin, veins, tendons, and flesh, corrupting these tissues and forming a long, thick, rough chain of nodules, with intense pain and fever, all suffused with blood. This nodular spreading is accompanied by breathlessness, cough, diarrhea, dryness of mouth, hiccups, vomiting, dizziness, confusion, discoloration, fainting, breaking of limbs, and loss of appetite, and it arises from the aggravation of phlegm and wind. From the combination of phlegm and bile, there arise fever, stiffness, sleep, drowsiness, headache, weakness and trembling of limbs, delirium, loss of appetite, and dizziness. Fainting, loss of digestive fire, breaking of bones, thirst, heaviness of the senses, accumulation of impurities, and coating occur as the disease spreads through the bodily channels. Usually affecting the stomach, it is not excessively painful in one place, but is covered with pustules, extremely yellow, red, or pale. It may be sticky, black, resembling soot, dirty, swollen, and heavy; after deep maturation, it is mostly moist when touched by heat and bursts open. Like ripened flesh, with exposed tendons and veins, it affects all parts with all symptoms, spreading everywhere and emitting the smell of a corpse. This spreading is called ‘muddy’. Due to external causes, such as injury, agitated blood and bile, wind produces spreading marked by nodules resembling horse gram, with eruptions, swelling, fever, pain, burning, and dark blood. The three pathologies caused by the channels are curable, and those arising from dual causes are without complications. However, those arising from all causes, or those invading the vital spots, are incurable, especially when tendons, veins, and flesh are ruptured, moist, and emitting a corpse-like odor. Dhanvantari then spoke of the origins of leprosy and other skin diseases. He said that improper eating and living, as well as actions such as slandering the virtuous, neglect, fighting, and theft, and sinful deeds both recent and past, drive impure substances into the veins. These impurities, joined with the bodily tissues, reach the skin, flesh, blood, and fat, corrupting and drying them up before emerging outward. They cause discoloration of the skin, and the remaining impurities manifest as leprosy and other skin diseases. When neglected over time, all the bodily channels are affected; having entered all tissues, both external and internal, these impurities disturb and overflow them. With sweat, moisture, and constriction, they produce minute and harsh worms, which successively invade the hair, skin, tendons, and vessels. This produces external leprosy, which appears as if covered with ash. Leprosy is said to be of seven kinds, arising from the humors singly, in pairs, or all together. Among the three humors, their combinations are further distinguished. Leprosy from wind is called Kāpāla, from bile Udumbara, and from phlegm arise Maṇḍala, Vicarcū, Ṛṣya, and those from wind and bile; Carma, Eka-kuṣṭha, Kiṭima, Sidhmā, Alasā, and Vipādikā. Those arising from wind and phlegm, and from phlegm and bile, are Dadru and Śatāruṣī; Puṇḍarīka, with blisters, Pāmā, and Carmadala as well. Of all these, Kākaṇa, Pūrvatrika, Dadru with Kākaṇa, Puṇḍarīka, Ryajihvā—these seven are regarded as the major types of leprosy. Thus, Dhanvantari revealed the intricate causes and manifestations of swelling, spreading diseases, and leprosy, emphasizing their roots in corrupted humors, impure substances, and improper actions, and describing their symptoms and classifications with great clarity for the benefit of Suśruta.