Preventing headaches in certain patients with chronic migraines. It is used for reducing the severity of abnormal head position and neck pain associated with neck problems. It may be used to reduce armpit sweating that does not respond to treatment with other medicines. It may also be used to treat muscle stiffness in the elbow, wrist, or fingers. It may also be used to treat loss of bladder control in certain patients. It may also be used to treat certain types of eyelid muscle spasms, eye focusing problems, or other conditions as determined by your doctor. Botox is a neurotoxin. It works by blocking nerve impulses to the muscles or sweat glands, temporarily paralyzing the muscle or gland.