Many things can cause a swollen penis. If you have penile swelling, your penis may look red and irritated. The area might feel sore or itchy.

The swelling can occur with or without unusual discharge, foul odor, or bumps. These symptoms could make it difficult to urinate or have sexual intercourse.

Since there are many causes for a swollen penis, it’s important to pay attention to other symptoms. This will help your doctor determine the underlying cause.

In rare cases, a swollen penis is a medical emergency. Conditions like priapism or paraphimosis require immediate help.

Read on to learn the common causes of penile swelling and what to do to treat it.

Penile swelling is a symptom of a health condition rather than a condition itself. It usually shows up with other symptoms, which can range from mild to severe.

Possible underlying causes include:

Balanitis

Balanitis is a common cause of penile swelling. It occurs when the penis head, also called the glans, is inflamed.

About 3 to 11 percent of males will experience balanitis in their lifetime. The condition usually affects uncircumcised males with poor hygiene habits.

Recurring balanitis is associated with poorly managed diabetes and immunodeficiency.

Common symptoms include:

Most cases are a result of an overgrowth of Candida albicans, a type of yeast that naturally occurs on the body. The second most common cause of balanitis is bacterial, due to a Streptococcus species.

While the condition isn’t a sexually transmitted infection (STI), the microorganisms that cause it can be physically transferred.

Allergic or irritant reaction

Another cause of penile swelling is contact dermatitis. This involves an allergic or nonallergic reaction to an irritating substance, such as:

In addition to swelling, you may have:

If you think you’re allergic or sensitive to something, stop using it immediately.

Urethritis

Inflammation of the urethra, known as urethritis, can cause penile swelling. The urethra carries urine from your bladder to your penis.

In the United States, urethritis affects 4 million people every year.

Typically, urethritis is a result of an STI. Neisseria gonorrhoeae (gonococcal urethritis) bacteria as well as nongonococcal bacteria can cause it.

Less common causes include irritating chemicals or injury from a urinary catheter.

Other symptoms include:

Priapism

A swollen penis might be a symptom of priapism. This condition is a prolonged erection that continues without sexual stimulation. In some cases, it can happen after sexual stimulation has occurred.

You may have:

  • an erection that lasts for more than four hours (without sexual stimulation)
  • progressive pain
  • erection without a fully rigid penis
  • fully rigid penis with soft head
Medical emergency

Call 911 or go to the nearest emergency room if you have an erection that’s painful, lasts longer than four hours, or any of the following apply:

  • You have sickle cell disease (a common cause).
  • You take intracavernosal drugs for erectile dysfunction.
  • You heavily use alcohol or drugs.
  • You’ve had damage to your penis during childbirth (perineal trauma).

Peyronie’s disease

Peyronie’s disease happens when plaque builds up in the penis below the skin. This can cause bumps that make the penis abnormally curve or bend.

Inflammation with swelling is the first symptom of Peyronie’s disease. Over time, the swelling can turn into a hard scar.

Other symptoms of Peyronie’s disease include:

  • bent or curved penis
  • painful erections
  • soft erections
  • lumps
  • painful sexual intercourse
  • erectile dysfunction

The cause of Peyronie’s disease isn’t clear. However, it’s associated with:

  • penis injury
  • autoimmune disease
  • connective tissue disorder
  • aging

Doctors estimate 6 out of 100 males between 40 and 70 years old have Peyronie’s disease. It can also affect younger men in their 30s.

Posthitis

If only your foreskin is swollen, you might have what’s called posthitis. Posthitis is inflammation of the foreskin. An overgrowth of fungus often causes it.

Posthitis often develops with balanitis.

Foreskin symptoms may include:

Balanoposthitis

Typically, balanitis and posthitis occur together. This is known as balanoposthitis. It’s inflammation of both the glans and foreskin.

Compared to balanitis, balanoposthitis is less common. It affects 6 percent of uncircumcised males.

Balanoposthitis causes penile swelling along with:

Paraphimosis

Paraphimosis is another cause of penile swelling that only affects uncircumcised males. It happens when the foreskin is stuck just behind the glans, causing constriction.

Additional symptoms include:

Paraphimosis may result from:

  • forgetting to pull the foreskin back down
  • infection
  • injury
  • incorrect circumcision
  • diabetes-related inflammation

Paraphimosis isn’t common. It affects about 1 percent of uncircumcised males over 16 years old.

If the foreskin can’t be pulled back, it can cut off blood flow and lead to tissue death in the glans.

Medical emergency

Paraphimosis is a medical emergency. Call 911 or go to the nearest emergency room if you’re having any of the symptoms mentioned above.

Penile cancer

In rare cases, penile swelling might indicate penile cancer.

Typically, skin changes are the first sign of penile cancer. Other symptoms may include:

  • skin thickening
  • redness
  • lump or ulcer
  • flat, blue-brown bumps
  • foul-smelling discharge under the foreskin
  • bleeding under the foreskin

You’re more likely to develop penile cancer if you:

  • are 60 or older
  • have poor personal hygiene
  • have phimosis
  • use tobacco products
  • have HPV

Penile cancer is extremely rare. In North America and Europe, less than 1 in 100,000 men are diagnosed with penile cancer.

If you have minor penile swelling, home remedies might provide relief. These include:

  • soaking in a warm bath
  • applying gentle pressure to your penis
  • applying an ice pack wrapped in cloth to your penis

It’s also best to avoid harsh soaps, lotions, and other potentially irritating substances.

The best treatment depends on your symptoms and cause of swelling. Medical treatments include:

  • antifungal cream
  • steroid cream
  • oral antifungal medicine
  • oral antibiotics
  • intravenous antibiotics
  • dorsal slit (surgically widening the foreskin)
  • circumcision

Your doctor might also prescribe a pain-relieving medication to help control pain.

If you have penile swelling that gets worse or doesn’t go away, visit your doctor. Also see your doctor after a penis injury.

Depending on your symptoms, your doctor might refer you to a urologist.

Your doctor might use the following to help diagnose your condition:

  • Medical history. They’ll ask about your sexual history, hygiene habits, and overall health.
  • Physical exam. In most cases, they can make a diagnosis by simply looking at your penis.
  • Swab test. If you have unusual discharge, they may send a sample of it to a lab. This will help determine what microorganisms are causing your symptoms.
  • Imaging tests. They might order an ultrasound, X-ray, CT scan, or MRI. These imaging tests produce detailed images of the soft tissues in your penis.
  • Biopsy. If they suspect penile cancer, they’ll request a biopsy. A piece of tissue from your penis will be sent to a lab for examination.

Penile swelling is a sign of an underlying medical condition. Depending on the cause, you might also have redness, itchiness, unusual discharge, or bumps.

There are many causes of penile swelling, so see your doctor if it gets worse or doesn’t go away. Many conditions can be diagnosed with a basic physical exam.

If you have an erection that lasts for more than four hours or the foreskin of your penis gets trapped behind the head, get emergency help.