[4] Roughly 90% of cases are the less serious distal hypospadias, in which the urethral opening (the meatus) is on or near the head of the penis (glans).

[7][8] Another model suggests hypospadias arises as a result of unerased epigenetic markers which canalize sexual development.

[4] It most often occurs by itself, without other variations, although in about 10% of cases it may be part of disorder of sex development condition or a medical syndrome with multiple abnormalities.

[11] The combination of hypospadias and an undescended testicle sometimes indicates a child has a difference of sex development condition, so additional testing may be recommended to make sure the child does not have congenital adrenal hyperplasia with salt wasting[clarify] or a similar condition where immediate medical intervention is needed.

[23] Animal studies have found that androgen antagonists during early fetal development cause elevated rates of hypospadias and cryptorchidism, however, in humans these traits rarely occur together.

[4] If this marks are sexually antagonistic, and if a subset of these epigenetic marks carry over generations, they are expected to produce mosaicism of sexual development in opposite-sex offspring, sometimes producing hypospadias or cryptorchidism when passed from a mother to son (feminizing the external genitalia).

[4] A 2022 study found additional evidence of atypical epigenetic methylation in foreskin tissue of hypospadias patients.

Chordee is a separate condition, but where it occurs, the downward curvature of the penis may be enough to make sexual penetration more difficult.

For these reasons or others, people with hypospadias may choose to seek urethroplasty, a surgical extension of the urethra using a skin graft.

[citation needed] Surgery can extend the urinary channel to the end of the penis, straighten bending, and/or change the foreskin (by either circumcision or by altering its appearance to look more typical ("preputioplasty"), depending on the desire of the patient.

"[27] A karyotype and endocrine evaluation should be performed to detect intersex conditions or hormone deficiencies that have major health risks (i.e. salt-wasting).

If the penis is small, testosterone or human chorionic gonadotropin (hCG) injections may be given with consent to enlarge it before surgery if this will increase the chance of a successful urethral repair.

In patients with severe hypospadias, surgery often produces unsatisfactory results, such as scarring, curvature, or formation of urethral fistulas, diverticula, or strictures.

[28] However, typical complications in urethroplasty for severe hypospadias can lead to long surgical cycles of failure and repair, and side effects may include loss of sexual or urinary function.

[29] Research suggests failure rates are higher when urethroplasty corrects a born condition rather than disease or injury[30] so patients and families considering surgery for hypospadias should have realistic expectations about the risks and benefits.

Numerous articles report testosterone injections or topical creams increase the length and circumference of the penis.

However, those with the most severe condition having a urinary opening in the scrotum and downward bending of the penis are often corrected in a two-stage operation.

[citation needed] Problems that can arise include a small hole in the urinary channel below the meatus, called a fistula.

The head of the penis, which is open at birth in children with hypospadias and is closed around the urinary channel at surgery, sometimes reopens, known as glans dehiscence.

[citation needed] Complications are usually corrected with another operation, most often delayed for at least six months after the last surgery to allow the tissues to heal sufficiently before attempting another repair.

[3] While most hypospadias repairs are done in childhood, occasionally, an adult desires surgery because of urinary spraying or unhappiness with the appearance.