Botox (onabotulinumtoxinA) is used to treat chronic migraines, overactive bladder, urinary incontinence from nerve conditions, muscle stiffness, cervical dystonia, eye muscle disorders, and severe underarm sweating. It is injected in small amounts into targeted muscles or glands by a healthcare provider. Botox works by blocking nerve signals to reduce muscle activity, helping relieve symptoms at the injection site.