Phimosis may be prevented by good hygiene. This includes fully pulling back the foreskin, so you can clean under it during bathing.
Paraphimosis can be prevented by carefully replacing the foreskin every time it is pulled back. If paraphimosis occurs, circumcision may be recommended to prevent it from happening again.
Prognosis
In most men, phimosis is not a serious problem and will not require treatment. However, it is not expected to improve on its own.
As noted above, paraphimosis is sometimes a medical emergency, and the penis may become permanently damaged if you do not seek immediate medical attention.