A purple-black and dull jar mark is a sign of blood stasis and cold. If a large black and purple mark appears on the jar, it indicates external wind and cold. If the marks do not subside for several days, it often indicates that the disease has been in progress for a long time and needs more treatment. Scattered purpura with varying depths is a sign of Qi stagnation and blood stasis. A pale purple and greenish jar mark with plaques suggests Qi deficiency and blood stasis. A bright red jar mark indicates Yin deficiency and fire. After suction and cupping, if there is no can mark or if there is one but it disappears immediately after cupping and returns to normal color, it indicates that the disease is still mild. However, in obese and anemic patients, there is often no suction and cupping marks. The area being suctioned and cupped has obvious suction and cupping signs within 5 minutes, indicating that the area is the one with the disease. If there are red dots concentrated near an acupuncture point after a large area of cupping on the back, it suggests that the acupuncture point is located in an abnormal internal organ.