"They can create a blockage in the pores and cause them to become clogged." "If the clogged pores are due to sweat or bacteria, an antibacterial cleanser may also be helpful. Clogged pores on breasts can be caused by a variety of things, such as bacteria, sweat, and oils. There are several ways to prevent and treat clogged pores on breasts, including using a gentle cleanser, wearing loose clothing, and avoiding harsh chemicals.