Other uses. Botox was used medically before it was used cosmetically. It is used to ease cervical dystonia or wry neck. This condition happens when the muscles in the neck force the head to twist toward one shoulder. Besides the awkwardness of this posture, the muscles in the neck and sometimes in the back become painful and tender. Botox is also used for overactive bladder because it calms down the nerves that make the muscles near the bladder go into spasm. These spasming muscles make the person feel the constant need to urinate. Botox is also used to control hyperhidrosis, which is excessive and embarrassing sweating. Botox also eases some of the symptoms of migraine headache. Doctors believe much of the pain of the headache is made by contracting muscles in the patient’s head and neck.