Blackheads are difficult to remove due to improper cleaning, sebaceous gland secretion, long-term spicy and stimulating diet and other reasons. 1. Improper cleansing: the skin itself is oily, the face loves oil, and at the same time did not do a good job of cleaning the skin, can lead to further increase in oil secretion and clogging of pores, oil and dust in the external environment, particles mixed, and ultimately will be hardened and blocked pores, is not easy to remove. 2. Excessive sebaceous gland secretion: If there is too much androgen in the body, it will prompt the sebaceous gland secretion of the face, which will also lead to the phenomenon that blackheads are easy to reappear after removing them, and it is difficult to remove them completely. 3. Improper diet: long-term like spicy and stimulating food, intake of fresh fruits and vegetables less, will also cause stimulation of sebaceous glands, stimulate the secretion of oil, so that blackheads recur. When blackheads recur and are difficult to remove, it is recommended to go to a regular medical institution for standardized treatment and not to blindly use medication on your own.