Scrotal swelling, the enlargement of the sac of skin that holds the testicles, can range from a benign condition to a medical emergency. The swelling is a physical manifestation of an underlying issue, which may be fluid buildup, an infection, or a structural problem. It may affect the entire scrotum or just one side. Any noticeable change, whether painful or not, requires consultation with a healthcare professional for correct diagnosis and appropriate treatment.
Causes Related to Fluid Buildup
Fluid accumulation around the testicle or within the scrotal tissues is a common source of non-painful enlargement. A hydrocele is a frequent cause, involving the collection of fluid in the thin sheath surrounding the testicle. This buildup can result from injury, inflammation, or infection, though many cases develop for no apparent reason. Hydrocele swelling often causes a feeling of heaviness or fullness, and in adults, it may enlarge during the day and decrease after lying down.
General scrotal edema is another fluid-related cause, where excess fluid accumulates in the soft tissues of the scrotal wall itself. This type of swelling is sometimes linked to systemic health issues, such as congestive heart failure or kidney problems, where the body struggles to manage fluid balance.
Scrotal lymphedema, a less common condition, involves the buildup of lymph fluid due to a blockage in the lymphatic system. Unlike hydroceles, this chronic swelling can extend to the surrounding genital areas. These fluid-related causes are typically not associated with acute pain or fever, distinguishing them from infectious conditions.
Causes Related to Infection and Inflammation
Infection and inflammation often cause swelling characterized by pain, warmth, and systemic symptoms like fever. Epididymitis is inflammation of the epididymis, the coiled tube on the back of the testicle that stores and carries sperm. In younger men, this condition is commonly caused by a bacterial infection, often originating from a sexually transmitted infection (STI) like chlamydia or gonorrhea.
In older men, epididymitis is frequently linked to the backflow of infected urine from the urinary tract, often involving bacteria like E. coli. Symptoms typically develop gradually, including scrotal pain that may spread to the groin, tenderness, and skin redness. Treatment usually involves antibiotics to clear the underlying bacterial infection.
Orchitis is inflammation of the testicle itself, which can occur alone or spread from epididymitis, a combined condition called epididymo-orchitis. While bacteria can cause orchitis, the mumps virus is a notable viral cause, especially in males who contract mumps after puberty. Orchitis symptoms are similar to epididymitis but involve more severe pain and swelling directly in the testicle.
If left untreated, severe infections can lead to complications like a scrotal abscess requiring drainage, or, in rare cases, testicular atrophy. Diagnosis often involves urine tests for bacterial presence and an ultrasound to visualize affected structures. Timely medical care helps prevent long-term issues.
Causes Related to Structural and Vascular Changes
Swelling can result from mechanical defects or issues with scrotal blood vessels. An inguinal hernia occurs when a portion of the intestine or fatty tissue pushes through a weak spot in the abdominal wall and descends into the scrotum. This creates a lump that may enlarge when coughing or straining, causing discomfort or pressure in the groin area.
If the herniated tissue becomes trapped (incarceration), the swelling can rapidly become painful, requiring emergency medical attention. Although more common in infants, adults can develop an inguinal hernia due to straining or pre-existing abdominal wall weakness.
A varicocele is another cause, involving the enlargement of veins inside the scrotum, often described as feeling like a “bag of worms.” Similar to varicose veins in the legs, varicoceles are caused by faulty valves that allow blood to pool instead of flowing toward the heart. The condition is more common on the left side due to anatomical differences in venous drainage.
Varicoceles often cause minimal pain or a dull ache that may worsen during the day or strenuous activity. While they typically do not cause acute, severe swelling, a varicocele can sometimes affect sperm quality and quantity due to the increased temperature from pooled blood.
Recognizing Medical Emergencies
Certain causes of scrotal swelling demand immediate medical attention, as a delay can lead to permanent testicular damage. Testicular torsion is the most time-sensitive emergency, occurring when the testicle rotates and twists the spermatic cord, cutting off the blood supply and leading to rapid tissue death.
Symptoms include the sudden onset of severe, excruciating pain, often accompanied by nausea and vomiting. The affected testicle may also appear higher than normal or at an unusual angle. Blood flow must be restored quickly, ideally within four to six hours of symptom onset, to maximize the chance of saving the testicle.
Any direct, severe trauma to the scrotum can also cause significant swelling and requires emergency evaluation to rule out internal injury. Signs like swelling following a direct strike, severe discoloration, or an inability to get comfortable should be treated as a medical crisis.