A pimple begins deep inside the skin when a hair follicle becomes blocked with trapped oil and dead skin cells. As this buildup increases, the swollen follicle starts pushing upward toward the surface. Pressure slowly rises inside the blocked pore and the surrounding tissue becomes irritated. The area can feel tight even before anything appears on the surface, and the follicle continues to climb toward the upper layers of the skin. The skin around the clog reacts with redness and swelling. The s