The monograph covers the issues of primary dysmenorrhea in girls under 18 in the absence of pathology on the side of the pelvic organs taking into account the criteria of connective tissue dysplasia of various degrees. The risk factors of juvenile dysmenorrhea development and peculiarities of the connective tissue state are revealed by estimating the content of oxy-proline in the urine formed at collagen structural substance decay in hypomagnesemia and steroid profile disorders and algorithms of diagnostics and treatment of juvenile dysmenorrhea are recommended.