The penis is one of the external
structures of the male reproductive
system. The penis has three parts: the
root, which attaches to the wall of the
abdomen; the body, or shaft; and the
penis, which is the cone-shaped end
(head). The opening of the urethra, the
tube that transports semen and urine, is
at the tip of the
The body of the penis is cylindrical in
shape and consists of three internal
chambers. These chambers are made up of
special, sponge-like erectile tissue.
This tissue contains thousands of large
caverns that fill with blood when the
man is sexually aroused. As the penis
fills with blood, it becomes rigid and
erect, which allows for penetration
during sexual intercourse. The skin of
the penis is loose and elastic to
accommodate changes in penis size during
Semen, which contains sperm (the male
reproductive cells), is expelled through
the end of the penis when the man
reaches sexual climax (orgasm).
Disorders of the penis can affect a
man’s sexual functioning and fertility.
What disorders affect the penis?
Some disorders that affect the penis
include the following:
Priapism is a persistent, often painful erection that can
last from several hours to a few days.
erection is not associated with sexual
activity and is not relieved by orgasm.
It occurs when blood flows into the
penis but is not adequately drained.
Common causes of
Alcohol or drug abuse (especially cocaine)
Certain medications, including some antidepressants and
blood pressure medications
Spinal cord problems
Injury to the genitals
Penile injection therapy (a treatment for erectile
Blood diseases, including leukemia and sickle cell anemia
Peyronie's disease is a condition in which a plaque, or hard
lump, forms on the penis. The plaque may
develop on the upper (more common) or
lower side of the penis, in the layers
that contain erectile tissue. The plaque
often begins as a localized area of
irritation and swelling (inflammation),
and can develop into a hardened scar.
The scarring reduces the elasticity of
the penis in the area affected.
Peyronie's disease often occurs in a mild form that heals without
treatment in six to 15 months. In these
cases, the problem does not progress
past the inflammation phase. In severe
cases, the disease can last for years.
The hardened plaque reduces flexibility,
causing pain and forcing the penis to
bend or arc during erection.
In addition to the bending of the penis,
disease can cause general pain as well
as painful erections. It also can cause
emotional distress, and affect a man’s
desire and ability to function during
The exact cause of
Peyronie's disease is unknown.
Cases that develop
quickly, last a short time and go
away without treatment most often are
due to a trauma (hitting or bending)
that causes bleeding inside the penis.
Some cases of
Peyronie’s disease, however,
develop slowly and are severe enough to
require surgical treatment. Other
possible causes of
Peyronie’s disease include:
an inflammation of blood or
lymphatic vessels. This inflammation
can lead to the formation of scar
Connective tissue disorders
— According to the National
Institutes of Health, about 30
percent of men with
disease also develop disorders that
affect the connective tissue in
other parts of their bodies. These
disorders generally cause a
thickening or hardening of the
connective tissue. Connective tissue
is specialized tissue—such as
cartilage, bone and skin—that acts
to support other body tissues.
— some studies suggest that a man
who has a relative with
Peyronie’s disease is at
greater risk for developing the
Balanitis is an inflammation of the skin covering the head of
the penis. A similar condition,
refers to inflammation of the head and
the foreskin. Symptoms of
include redness or swelling, itching,
rash, pain and a foul-smelling
Balanitis most often occurs in men and boys who have not been
circumcised (had their foreskin
surgically removed), and who have poor
hygiene. Inflammation can occur if the
sensitive skin under the foreskin is not
washed regularly, allowing sweat,
debris, dead skin and bacteria to
collect under the foreskin and cause
irritation. The presence of tight
foreskin may make it difficult to keep
this area clean and can lead to
irritation by a foul-smelling substance
that can accumulate under the foreskin.
Other causes may include:
— Dermatitis is an inflammation of the
skin, often caused by an irritating
substance or a contact allergy.
Sensitivity to chemicals in certain
products—such as soaps, detergents,
spermicides—can cause an allergic
reaction, including irritation, itching
and a rash.
— Infection with the yeast
(thrush) can result in an itchy, spotty
rash. Certain sexually transmitted
diseases—including gonorrhea, herpes and
syphilis—can produce symptoms of
In addition, men with diabetes are at
greater risk for
balanitis. Glucose (sugar) in the
urine that is trapped under the foreskin
serves as a breeding ground for
Persistent inflammation of the penis
head and foreskin can result in
scarring, which can cause a tightening
of the foreskin (phimosis)
and a narrowing of the urethra (tube
that drains urine from the bladder).
Inflammation also can lead to swelling
of the foreskin, which can cause injury
to the penis.
Phimosis is a condition in which the foreskin of the penis
is so tight that it cannot be pulled
back (retracted) to reveal the head of
Paraphimosis occurs when the
foreskin, once retracted, cannot return
to its original location.
Phimosis, which is seen most often in children, may be present at
birth. It also can be caused by an
infection, or by scar tissue that formed
as a result of injury or chronic
inflammation. Another cause of
which leads to scarring and tightness of
the foreskin. Immediate medical
attention is necessary if the condition
makes urination difficult or impossible.
Paraphimosis is a medical emergency that can cause serious
complications if not treated.
may occur after an erection or sexual
as the result of injury to the head of
the penis. With
paraphimosis, the foreskin
becomes stuck behind the ridge of the
head of the penis. If this condition is
prolonged, it can cause pain and
swelling, and impair blood flow to the
penis. In extreme cases, the lack of
blood flow can result in the death of
tissue (gangrene), and amputation of the
penis may be necessary.
A rare form of cancer, penile cancer
occurs when abnormal cells in the penis
divide and grow uncontrolled. Certain
benign (non-cancerous) tumors may
progress and become cancer.
The exact cause of penile cancer is not
known, but there are certain risk
factors for the disease. A risk factor
is anything that increases a person’s
chance of getting a disease. The risk
factors for cancer of the penis may
include the following:
who are not circumcised at birth
have a higher risk for getting
cancer of the penis.
papillomavirus (HPV) infection—HPVs
are a group of more than 70 types of
viruses that can cause warts (papillomas).
Certain types of
HPVs can infect the
reproductive organs and the anal
area. These types of
HPVs are passed from one person
to another during sexual contact.
exposes the body to many
cancer-causing chemicals that affect
more than the lungs.
secretions from the skin can accumulate
under the foreskin of the penis. The
result is a thick, bad-smelling
smegma. If the penis is not
cleaned thoroughly, the presence of
cause irritation and inflammation.
is a condition in which the foreskin
becomes constricted and difficult to
o Treatment for psoriasis—The
skin disease psoriasis is sometimes
treated with a combination of medication
and exposure to ultraviolet light.
cases of penile cancer occur in men over