In most cases, cotton swabs cannot touch the eardrum. The human external ear canal has a certain curvature and is not straight. The skin of the ear canal is rich in sensory nerve endings, so if a cotton swab is slightly inadvertent or digs deeper, the skin of the ear canal will cause obvious pain and cough reflex, forcing the action to end. In most cases, the swab will not touch the eardrum. However, in some special cases, such as being bumped by someone else while pulling out the ear or accidentally falling or falling, the swab may be pushed deep into the ear canal, damaging the wall of the ear canal and touching the eardrum, which may even cause perforation of the eardrum, resulting in bleeding, pain, hearing loss and other symptoms.