Acne on the face but hard bumps may be nodular acne, caused by excessive androgens, bacterial infections, and blockage of follicular openings. 1. Excessive androgen: When the body secretes too much androgen, it can promote hypersecretion of sebum in the sebaceous glands, which can easily lead to obstruction of sebum excretion and accumulation of sebum, resulting in the appearance of common acne on the face. 2. Bacterial infections: When the hair follicles are infected with bacteria such as Propionibacterium acnes, Fusobacterium ovale, Staphylococcus epidermidis, etc., it can lead to over-keratinization of the openings of sebaceous glands of the hair follicles and blockage of the openings of sebaceous glands, which can lead to an inflammatory reaction of the hair follicles. This in turn leads to acne on the face. 3. Clogged follicle openings: When the sebaceous glands produce a lot of sebum, the follicle openings are easily clogged, resulting in the formation of closed pimples. When the blocked follicles are combined with more serious inflammatory infections, not only will there be abscesses and pustules. And because of the large number of inflammatory cells and inflammatory tissues gathered in the skin, cystic nodules can be formed. When you have hard pimples on your face, you should keep your facial skin clean, avoid applying cosmetics to the affected area, and avoid squeezing the pimples with your hands, so as to avoid infection and aggravation of the symptoms. At the same time, you should eat a light diet, eat more fresh fruits and vegetables, eat less spicy and stimulating food, should be regular routine, to ensure sufficient sleep. If the symptoms are serious, it is recommended to go to the dermatology department of the hospital as soon as possible to clarify the cause of the disease and carry out targeted treatment.