Phimosis. Phimosis is physiologic (normal) in babies, by 3-4 years of age the majority (90%) resolve spontanously due to intermittent erections , by 18 years of age only 1% or less have pessitent non retractile foreskin the most common cause of pathologic phimosis is repeated infections (balanitis).
Congenital/acquired. Phimosis is physiologic & thus normal in almost all baby boys. It resolves spontaneously in most boys as they grow. Persistently tight foreskin which never opened up or can not retract is phimosis. Can also be caused by balanitis or posthitis (inflammation of glans &/or inner foreskin) forceably retracting child's foreskin->splits then scars-> phimosis. Balanitis xerotica obliterans also a cause.
Inflammation. Phimosis is thickening and narrowing the foreskin which causes pain and discomfort with retraction of the foreskin. The skin can become red, tender, and tight restricting its retraction over the glans penis (head of the penis). Forecful retraction, chronic infections of the foreskin, trauma to the foreskin, and uncontrolled diabetes can causes phimosis.
Born with it ... Males are born with highly variable length of their foreskin covering glans penis. After birth, physical growth along with the process of desqaumation between glans penis and foreskin gradually makes foreskin retract to eventually expose the glans penis completely for some, partially for most, but still leave tight and long, even non-retractable foreskin for few. So, phimosis is an inborn disorder.