Myotonic dystrophy (DM) is an autosomal dominant inherited disorder, often familial. As patients have diverse symptoms, health support needs differ but research is lacking on MD management in Japan. A nationwide survey of medical care and treatment for MD patients, including those with neonatal to adolescent onsets, was conducted in 2018. Respondents were registered in the Japanese national registry (Remudy) or were recruited by doctors specializing in neuromuscular diseases. We obtained 342 valid responses for 813 questionnaires, including 87 with congenital / childhood onset. We divided respondents into 3 groups by onset age: group 1, 28 patients (8.2%) ˂4 weeks, group 2, 4 (1.2%) ˂12 months, and group 3, 55 (15.5%) 1-19 years. There were no gender differences. Average patient ages at survey were 12.5, 25.4, and 31.5 years, and the response ratio of patients having a family history of DM were 71.8%, 100%, 60%, respectively. Group 1 had clinical symptoms at birth including asphyxia, while group 3 tended to show myotonia symptoms leading to DM1 diagnosis. Finger dysfunction and fatigability were common chief complaints in groups 1 and 3 (response ratio ∼70% in group 1 and ≥95% in group 3). Over 80% of group 1 but only 31% of group 3 patients required rehabilitation. More than one third of respondents in each group were dissatisfied with health support or medical care. We found that 16% of respondents had no chance to consult neuromuscular specialists because of distance or they lacked information about such specialists. We ascertained patients’ actual conditions, at different ages, and with different clinical types. Since necessary information and health support systems vary according to patient growth, development and disease evolution, appropriate medical services should ideally be provided whenever needed. This valuable information could contribute to provide MD patients standardized medical services.