Take psoriasis. In Western medicine, the cause of psoriasis is unknown, although it is believed to be a hereditary skin condition, triggered by infection and mental factors. In Chinese medicine, one of the causes of psoriasis is pathogenic Wind which incubates in the body. This transforms into Heat, and Wind and Heat struggle in the skin, resulting in the scaly, itchy patches. A Chinese medicine practitioner might prescribe herbs to clear the Heat, resolve toxins, and expel Wind.
However if there is a lot of Heat in the body that needs to be removed, the patient might have a blood cupping treatment, like the patient in the photo. Small punctures are made near an acupuncture point, then a glass cup which has been heated with fire is placed over the point. Because the heat creates a vacuum, the cup sticks to the skin and is left there for around 10 minutes, at which time the vacuum draws out blood. It might not be a pretty sight but it is a very effective way of removing Heat from the body.