Blackheads are a type of non-inflammatory acne caused by clogged hair follicles with oil, dead skin cells, and bacteria. When the blackhead is removed, the pore can look enlarged, giving the appearance of a hole. It is possible for blackheads to fill back up, as the factors causing them may still be present. Maintaining a good skincare routine, including cleansing, exfoliating, and using products with ingredients like salicylic acid or retinoids, can help prevent blackheads from recurring. However, if you have persistent concerns or issues with blackheads, consider consulting a dermatologist for personalized advice and treatment options.