Acne can destroy self esteme. For reasons no one completely understands, pores of the skin (follicles) sometimes get blocked. Skin oil (sebum) which normally drains to the surface of the skin gets blocked and bacteria begin to grow. Whiteheads and blackheads start out as a "microcomedone". A micromedone is a blockage in the pore of the skin. The natural progression is for the micromedone to become a comedone, which is the scientific name for a whitehead or a blackhead.
Witeheads and black heads are considered Acne. Both whiteheads and blackheads after the bacteria start to grow beneath the pore blockage (micromedone). Whether the blockage expresses itself as a blackhead or a whitehead, they are both filled with trapped oil and bacteria. See the link for proper acne treatments!