A hard black bag on the face is painless and itchy. Most of them are caused by blackhead acne and sebaceous cysts, which can be treated according to the causes. 1. Blackheads: due to exuberant sebum secretion and blockage of follicular opening leading to sebum excretion obstacles, resulting in the formation of acne, when the oil in the follicular opening and the air combined with oxidation, blackheads will appear. 2. Sebaceous cysts: due to sebaceous gland excretory tube blockage, causing sebum retention to form a cystic swelling, the center can be seen in the black pinpoint size of the depression, most common in the head and face, neck and chest and back, if the secondary infection can be painful, pus symptoms. For a black hard bag on the face does not hurt and itchy phenomenon, it is recommended to go to the hospital in a timely manner, improve the relevant examination, symptomatic treatment.