Dhanvantari, the divine physician, spoke with clarity and compassion about the origins and manifestations of leprosy and skin diseases. He explained that these afflictions often arise due to improper eating and living habits, as well as actions such as slandering the virtuous, neglect, fighting, and theft. Both recent and past sinful deeds drive impure substances into the veins, which then travel to the skin, flesh, blood, and fat. These impurities corrupt the tissues, drying them up and eventually emerging outward, causing discoloration of the skin. The remaining impurities manifest as leprosy and other skin diseases. When such conditions are neglected over time, all the bodily channels become affected. The impurities enter both external and internal tissues, disturbing and overflowing them. With sweat, moisture, and constriction, minute and harsh worms are produced, which successively invade the hair, skin, tendons, and vessels. This process gives rise to 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—wind, bile, and phlegm—their combinations produce various forms of leprosy. Leprosy from wind is called Kāpāla; from bile, Udumbara; and from phlegm, Maṇḍala, Vicarcū, Ṛṣya, and those from wind and bile. Other types include 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, and Ryajihvā—these seven are considered the major types of leprosy. Their symptoms are diverse: excessively smooth or rough to the touch, sweating or dryness, discoloration, burning, itching of the skin, numbness, pricking pain, swelling, and darkness. Severe pain in the sores, rapid onset and long duration, and roughness even after healing are common. With slight cause, they flare up greatly. Early signs include goosebumps and blackness of the blood. When the disease is black, red, dry, rough, and thin like a skull, spread out in shape, and scattered with corrupted hairs, it is recognized as Kāpāla leprosy, marked by much pricking pain and irregularity. Leprosy resembling the fruit of the Udumbara tree is called Audumbara; it is round, with thick edges, and marked by intense burning and pain. It remains uncovered, does not spread, is worm-infested like Udumbara, firm, true, heavy, oily, white or red, and accompanied by impurities. Another type, Maṇḍala, has tails attached to each other, much itching, discharge, and worms; it appears smooth and yellowish. Vicarcikā is dark, with itching and pimples, moist, rough, with red inside, dark within, and raised. The carmākhya leprosy is described as having the appearance of a deer's tongue, with many worms, and is rough to the touch like elephant skin. Kiṭima does not sweat, resembles fish scales, is dry, fiery in color, unpleasant to touch, itchy, rough, and grayish-black. Another type is dry inside, oily outside, sheds dust when rubbed, smooth to the touch, thin, oily, clear, and like the blossom of sweat. Vipādikā is marked by upward emaciation, covered with clusters of intense itching, and red, thread-like lines on the hands and feet. Some types are marked by severe pain, intense itching, filled with red pimples, spreading widely, and resembling the color of dūrvā grass or the atasi flower. Dadru is a raised, circular lesion, itchy, with a thick base, constant burning pain, red discharge, and many sores. It is accompanied by burning, moisture, and pain, often recurring in every birth; pale, circular, tinged with red, with itching, burning, and pain. Puṇḍarīka is raised and filled with redness, like a lotus leaf with water, marked by blisters that are white and reddish. Pāmā is characterized by blisters and pimples, with itching, moisture, and pain; fine, dark-reddish, dry, mostly found on the buttocks, hands, and elbows. Kākaṇa is painful to touch, with itching, redness, and intense burning; it is a red patch or skin lesion with severe burning and pain. Kākaṇa is first red, then black, resembling triphalā; it may have all dark features, each arising from its own cause. To differentiate among the humors, one should indicate the signs and actions as prescribed. Leprosy that follows all humors should be abandoned. Leprosy that resides in the bone, marrow, or semen is difficult to cure; that which is in the fat is manageable, and that which is in the skin, flesh, or bone is chronic. Leprosy arising from kapha and vāta, limited to the skin or impure, is not difficult; when it remains in the skin, there is discoloration and dryness in the body. Sweating, heat, and swelling occur in the blood and flesh; blisters on the hands and feet, and more so at the joints, are due to affliction. Frequent combination of humors causes destruction in the fat; there is no clear sign in the marrow, bone, eyes, or voice. When there is a wound, worms in the semen, or affliction of one's wife and children, all the previous signs appear in animals and others as well. Vitiligo (śvitra), arising solely from wood (kaṣṭha), is severe and dreadful; it is described as exuding, and based on the disturbance of all three humors. From wind, the lesion is dry and reddish; from bile, it is coppery, like a lotus petal, always burning, destroying hair; from phlegm, it is white, dense, and heavy. With itching, it gradually becomes red, affecting flesh and fat; by its color, both types are recognized, and the severity increases progressively. If it is not white, has abundant hair, is not attached, is new, and not burned by fire, then the leukoderma is curable; otherwise, it should be avoided. If it arises recently in the genital area, palm, or lips, the leukoderma should especially be avoided by those seeking success. Thus, Dhanvantari revealed the intricate causes, symptoms, and classifications of leprosy and skin diseases, guiding all toward understanding and discernment in their treatment and avoidance.