There are no tests for premature ejaculation as it is a self-reported diagnosis. Your doctor will ask questions about your sexual history (including how long the premature ejaculation has been happening and when it first happened) and will try to determine the cause of premature ejaculation based on your responses.
Your local doctor can help in the diagnosis and treatment of premature ejaculation. Your doctor may refer you to a specialist, such as a urologist or sex therapist, if needed.