Generalized Myotonia of Becker, also known as Becker disease, is a rare genetic disorder that affects muscle function. People with this condition experience muscle stiffness and difficulty relaxing their muscles after contraction. Synonyms for the disorder include Becker's myotonia, Myotonia Congenita of Becker, and generalized myotonia. These terms are often used interchangeably to describe the same condition. While the exact prevalence of Generalized Myotonia of Becker is unknown, it is estimated to affect approximately 1 in 10,000 individuals. Symptoms usually manifest in childhood or adolescence and can vary in severity. Treatment options primarily focus on managing symptoms through physical therapy, medication, and lifestyle modifications.