Orchitis (or-KIE-tis) refers to infection or swelling and irritation, called inflammation, of one or both testicles. Infections are common causes of orchitis. These include sexually transmitted infections (STIs) and infection with the mumps virus.

Orchitis often is linked with an infection of the epididymis, which is the coiled tube at the back of the testicle that stores and carries sperm. The infection of the epididymis is called epididymitis. With orchitis, the condition is called epididymo-orchitis.

Orchitis may cause pain and swelling. It is typically treated with supportive underwear, cold packs, medicines called anti-inflammatories and, in some instances, medicines called antibiotics. But it can take several weeks or even months for tenderness in the scrotum to go away.

Rarely, severe orchitis can affect being able to have children, called fertility. This most often happens in people who get the infection during childhood or the teen years.

Orchitis symptoms most often come on quickly. They can include:

• Swelling in one or both testicles.
• Pain ranging from mild to very bad.
• Fever.
• Nausea and vomiting.
• Feeling ill, called malaise.

When to see a doctor

For pain or swelling in your scrotum that comes on quickly, see your healthcare professional right away.

A number of conditions can cause testicle pain. Many go away on their own. But some need treatment right away.

One such condition involves twisting of the spermatic cord, called testicular torsion. The pain of this might feel like the pain of orchitis. Your healthcare professional can do tests to find out which condition is causing your pain.

Factors that raise the risk of orchitis include untreated conditions that block the urinary tract. These include prostate enlargement or scar tissue in the urethra, called urethral stricture.

Procedures done through the urethra also raise the risk of orchitis. These include having a tube, called a catheter, or a scope in the bladder.

The main risk factor for mumps orchitis is not getting the mumps vaccine.

Sexual behaviors that can lead to STIs put you at risk of sexually transmitted orchitis. Those behaviors include having:

• More than one sexual partner.
• Sex with a partner who has an STI.
• Sex without a condom.
• A personal history of an STI.

Most often, orchitis gets better with supportive care. It can take several weeks or months before the pain and swelling go away. Rarely, complications of orchitis may include:

• Testicular atrophy. Over time, orchitis can cause the affected testicle to shrink.
• Scrotal abscess. The infected tissue fills with pus.
• Infertility. Sometimes, orchitis can cause you to not be able to have a child, called infertility. Or it can cause the body to make too little testosterone, a condition called hypogonadism. But these are less likely to happen if orchitis affects only one testicle.

To help prevent orchitis:

• Get the vaccine against mumps, the most common cause of viral orchitis.
• Practice safe sex to help protect against STIs that can cause bacterial orchitis.
• Talk with your healthcare professional if you have trouble with urination. That may mean you have a blockage or other condition that can lead to orchitis.

Your healthcare professional starts with your medical history and a physical exam. The exam checks for enlarged lymph nodes in your groin and an enlarged testicle on the affected side. You also might have a rectal exam to check for prostate enlargement or tenderness.

Tests might include:

• STI screen. If you have discharge from your urethra, your health professional puts a narrow swab into the end of your penis to get a sample of the discharge. The sample goes to a lab to be checked for gonorrhea and chlamydia. Some STI screens are done with a urine test.
• Urine test. A sample of your urine goes to a lab for study. The test can rule out bacterial infection.
• Ultrasound. This imaging test is to find the cause of testicular pain. Ultrasound with color Doppler can show if the blood flow to your testicles is lower than it should be. This could mean you have torsion. A higher than usual blood flow helps confirm the diagnosis of orchitis.

Treatment depends on the cause of orchitis.

Treating bacterial orchitis

Antibiotics treat bacterial orchitis and epididymo-orchitis. If the cause of the bacterial infection is an STI, your sexual partner also needs treatment.

Take all the antibiotics your healthcare professional prescribes, even if your symptoms ease sooner. This is to make sure that the infection is gone.

Your scrotum may be tender for several weeks or months after treatment. Rest, support the scrotum with an athletic strap, apply cold packs and take medicine to help relieve pain.

Treating viral orchitis

Treatment aims to ease symptoms. You might:

• Take nonsteroidal anti-inflammatory medicines, such as ibuprofen (Advil, Motrin IB, others) or naproxen sodium (Aleve). Be sure to talk with your healthcare professional before taking these medicines if you take blood thinners or have kidney disease.
• Rest in bed with your scrotum raised.
• Use cold packs.

Most people with orchitis start to feel better in 3 to 10 days. But it can take a few weeks for the scrotum to stop being tender. Sometimes, the pain and swelling can last for several months.

To ease discomfort:

• Rest in bed.
• Lie down so that your scrotum is raised.
• Put cold packs on your scrotum.
• Don't lift heavy objects.

You might be sent to a specialist in urinary issues, called a urologist. Here's some information to help you get ready for your appointment.

What you can do

Make a list of:

• Your symptoms and when they began.
• Your childhood illnesses and vaccines. Include recent illnesses, especially STIs or mumps.
• All medicines, vitamins or other supplements you take, including doses.
• Questions to ask your healthcare team.

For orchitis, questions might include:

• What's the most likely cause of my symptoms?
• What are other possible causes?
• What tests do I need?
• What treatments are there?
• How long will it take before I start to feel better?
• Will this condition affect whether I can have children?
• Do I need to restrict my sexual activity?

Be sure to ask all the questions you have.

What to expect from your doctor

Your healthcare professional is likely to ask you questions, including:

• How bad are your symptoms?
• What treatments have you tried?
• What, if anything, seems to ease your symptoms?
• What, if anything, appears to make your symptoms worse?
• Do you practice safer sex? How many partners do you have? Do you use a condom?