Testicular pain has a wide range of causes, from infections and structural issues to conditions that originate outside the scrotum entirely. The most common causes are epididymitis (infection or inflammation of the tube behind the testicle), testicular torsion, varicoceles (enlarged veins), and inguinal hernias. Some causes resolve on their own, while others require emergency treatment within hours.
Torsion: The Emergency That Can’t Wait
Testicular torsion happens when the spermatic cord twists, cutting off blood flow to the testicle. The pain is sudden and severe, often hitting without warning. You may also notice swelling, nausea or vomiting, abdominal pain, or that one testicle sits higher than usual or at an odd angle. Some people develop a fever or feel the urge to urinate frequently.
Time matters enormously with torsion. A systematic review of over 1,200 patients found that when surgery happens within 6 hours of pain onset, 97% of testicles are saved. Between 7 and 12 hours, that drops to 79%. By 13 to 24 hours, survival falls to 54%, and beyond 24 hours, only about 18% of testicles can be saved. This is why sudden, severe scrotal pain warrants an emergency room visit, not a wait-and-see approach.
Torsion is most common in adolescents and young men, though it can happen at any age. Surgery involves untwisting the cord and stitching the testicle in place to prevent it from twisting again. Surgeons typically secure both testicles during the procedure, since the anatomy that allows torsion on one side is usually present on both.
Infections and Inflammation
Epididymitis, an infection of the coiled tube that sits behind each testicle, is the single most common cause of scrotal pain in adults. The pain typically builds over days rather than striking all at once, which helps distinguish it from torsion. You may notice swelling, warmth, redness, or pain that worsens throughout the day.
The cause depends largely on age and sexual activity. In sexually active men under 35, the infection is most often caused by the same bacteria responsible for chlamydia or gonorrhea. In older men, the culprit is more commonly the type of bacteria found in urinary tract infections, particularly in those with prostate enlargement or who’ve recently had a urological procedure. Antibiotics clear most cases within one to two weeks, though swelling can linger longer.
Orchitis, inflammation of the testicle itself, sometimes accompanies epididymitis. It can also occur on its own, most notably as a complication of mumps in post-pubertal males.
Varicoceles
A varicocele is an enlargement of the veins inside the scrotum, similar to varicose veins in the legs. They’re detectable in about 15% of the general adult male population and appear overwhelmingly on the left side due to differences in how blood drains from each testicle.
Most varicoceles cause no symptoms at all. Among men who have them, only about 2 to 10% experience pain. When pain does occur, it tends to be a dull, aching heaviness that worsens after prolonged standing, exercise, or hot weather and improves when you lie down. A varicocele often feels like a “bag of worms” above the testicle. Treatment is only needed when pain is persistent or when fertility is a concern, since varicoceles can affect sperm production.
Referred Pain From Other Areas
Not all testicular pain starts in the testicle. The nerves that supply the scrotum share pathways with nerves from the ureter, lower back, and hip. This overlap means a problem elsewhere in the body can produce pain that you feel in the testicle, even though the testicle itself is perfectly healthy.
Kidney stones are the classic example. A small stone in the lower ureter can cause pain felt mainly in the scrotum because the same spinal nerves (at the T10 through L2 levels) supply both the ureter and the scrotal area through shared nerve branches. The pain may come in waves, and you might also notice blood in your urine or pain in your flank or lower back. Herniated discs in the lower spine and hip joint problems can produce a similar effect.
Inguinal Hernias
An inguinal hernia occurs when tissue, usually part of the intestine, pushes through a weak spot in the abdominal wall near the groin. Because the inguinal canal runs down into the scrotum, a hernia can cause scrotal pain, swelling, or a dragging sensation that worsens with coughing, lifting, or straining. The pain often improves when lying down. If a hernia becomes strangulated, meaning its blood supply is cut off, the pain becomes sudden and severe, and this requires emergency surgery.
Pain After Vasectomy
Post-vasectomy pain is more common than many men expect. A meta-analysis found that about 15% of men experience some degree of testicular pain after the procedure. The rate was higher for traditional scalpel vasectomy (24%) compared to the no-scalpel technique (7%).
Most of this pain is mild and temporary. However, roughly 5% of men develop what’s called post-vasectomy pain syndrome, where the pain persists for months, interferes with daily activities, and may require further treatment. The exact mechanism isn’t fully understood, but it likely involves pressure buildup, nerve irritation, or inflammation at the vasectomy site.
Chronic Scrotal Pain
When testicular pain lasts longer than three months and interferes with daily life, it’s classified as chronic scrotal content pain. This can be one of the more frustrating diagnoses because the cause isn’t always obvious. Potential contributors include nerve entrapment (particularly after inguinal hernia repair), pelvic floor muscle tension, post-vasectomy changes, or lingering effects of a prior infection.
Some cases trace back to problems outside the scrotum entirely, including vertebral disc disease, hip pathology, or even retroperitoneal tumors. When no clear structural or infectious cause is found, treatment focuses on pain management, pelvic floor physical therapy, and sometimes nerve blocks to identify which nerve pathway is involved.
How Testicular Pain Is Diagnosed
The first and most important step in diagnosis is distinguishing emergencies, primarily torsion, from less urgent causes. A doctor will assess how quickly the pain started, whether it’s constant or intermittent, and whether it’s accompanied by fever, nausea, or changes in urination.
Ultrasound with Doppler imaging is the standard imaging tool. It checks blood flow to the testicle (reduced flow suggests torsion) and can identify infections, fluid collections, and structural abnormalities. Its accuracy varies by condition: for inflammatory problems like epididymitis, sensitivity and specificity both exceed 96%. For varicoceles, sensitivity reaches 93%. Torsion is trickier, with ultrasound sensitivity around 62%, partly because partial or intermittent torsion can be difficult to catch on a single scan. When torsion is strongly suspected based on symptoms, surgeons often proceed directly to the operating room rather than waiting for imaging.
Symptoms That Need Immediate Attention
Sudden, severe pain in the testicle is the hallmark red flag. Pain that comes on rapidly and intensely should be treated as torsion until proven otherwise. Testicle pain accompanied by nausea, fever, chills, or blood in your urine also warrants urgent evaluation. Gradual, mild pain that comes and goes is less likely to be an emergency, but persistent pain lasting more than a few days deserves a medical visit to rule out infection or structural issues that benefit from early treatment.