It refers to multiple abscess occurring in the deep areas of the muscles. It is believed in Chinese medicine that this disease is usually caused by stagnation of qi and blood due to obstruction of the meridians and collaterals, resulted from circulation of pathogenic toxins in the blood vessels because of insufficiency of the anti-pathogenic ability.Its clinical feature is diffuse tumefaction and pain in the infected areas initially, with normal skin color. It happens frequently in the areas with thick muscles of the four limbs and body trunk. Very often, it has not been cured in one area and appears in another area again. Because of the different causative factors, there are different names. For instance, multiple abscess occurring in summer and autumn is called multiple abscess of summer dampness. Multiple abscess caused by furuncle and boil is termed multiple abscess of residual toxins. Multiple abscess caused by retention of postpartum lochia or traumatic injury is called multiple abscess of stagnant blood. Multiple abscess happening in the iliac fossa is called multiple abscess of the iliac fossa. It is similar to pyemia in Western medicine, abscess in the deep position of the muscles and abscess of the lilac fossa.