Unilateral testicular pain is a common urological complaint that can range from mild discomfort to severe, acute pain requiring urgent medical attention. This type of pain, affecting only one testicle, can be caused by a variety of conditions, some benign and others potentially life-threatening. Accurate and timely diagnosis is critical because certain causes, such as testicular torsion, require immediate intervention to prevent long-term complications, including loss of the testicle. Understanding the differential diagnosis of unilateral testicular pain helps healthcare providers assess symptoms effectively, prioritize care, and guide appropriate treatment. Awareness of these causes is equally important for patients to seek timely medical evaluation.
Common Causes of Unilateral Testicular Pain
Unilateral testicular pain can arise from multiple sources, including urological, infectious, traumatic, and referred pain from adjacent structures. Identifying the underlying cause involves a detailed history, physical examination, and, in some cases, imaging or laboratory tests.
Testicular Torsion
Testicular torsion is an acute urological emergency in which the spermatic cord twists, cutting off blood supply to the testicle. This condition commonly affects adolescents and young adults but can occur at any age. Key features include sudden onset of severe unilateral testicular pain, swelling, nausea, and vomiting. Physical examination may reveal a high-riding testicle with abnormal orientation and absent cremasteric reflex. Rapid diagnosis is critical because the viability of the testicle decreases significantly if detorsion is not performed within 6 hours. Surgical intervention, often an orchidopexy, is required to restore blood flow and prevent recurrence.
Epididymitis
Epididymitis is inflammation of the epididymis, commonly caused by bacterial infections, including sexually transmitted infections like chlamydia and gonorrhea, or urinary tract pathogens such as Escherichia coli. Symptoms often develop gradually, presenting as unilateral testicular pain, swelling, and tenderness in the posterior aspect of the testicle. Patients may also experience fever, dysuria, or urethral discharge. Clinical evaluation includes palpation of the epididymis, urinalysis, and sometimes ultrasound to rule out torsion. Treatment typically involves antibiotics, scrotal support, and anti-inflammatory medications.
Orchitis
Orchitis refers to inflammation of the testicle itself and may occur alongside epididymitis. Viral infections, particularly mumps, are common causes in post-pubertal males. Symptoms include unilateral testicular pain, swelling, tenderness, and systemic signs such as fever. Physical examination may reveal diffuse testicular enlargement and tenderness. Management is generally supportive, including analgesics, scrotal elevation, and rest, with antibiotics reserved for suspected bacterial causes.
Inguinal Hernia
An incarcerated or strangulated inguinal hernia can present with unilateral testicular pain, often accompanied by swelling and tenderness in the groin. Pain may radiate to the testicle due to shared nerve pathways. Patients may report a bulge in the groin area that becomes more prominent when standing or straining. Immediate surgical evaluation is warranted for suspected strangulation to prevent tissue necrosis.
Hydrocele and Varicocele
Hydrocele, the accumulation of fluid around the testicle, usually presents as painless swelling but can cause discomfort if large. Varicocele, the dilation of the pampiniform plexus of veins in the scrotum, is more common on the left side and may result in a dull, aching unilateral pain. Physical examination, often with the patient standing and performing a Valsalva maneuver, helps in diagnosis. Ultrasound can confirm the presence of fluid or venous dilation.
Traumatic Causes
Direct trauma to the testicle, such as from sports injuries, accidents, or falls, can lead to unilateral testicular pain. The severity ranges from mild contusions to testicular rupture, which requires urgent surgical intervention. Symptoms may include swelling, bruising, tenderness, and in severe cases, hematoma formation. Prompt evaluation with physical examination and ultrasound is essential to assess testicular integrity.
Referred Pain Causes
Unilateral testicular pain may also result from conditions outside the testicle, a phenomenon known as referred pain. Common sources include
- Renal or Ureteral StonesPain may radiate from the flank or lower abdomen to the testicle due to shared nerve pathways.
- AppendicitisInflammation of the appendix, particularly in retrocecal positions, can cause pain that radiates to the right testicle.
- Hip or Spinal ConditionsNerve compression or musculoskeletal disorders in the lumbar spine or hip can mimic testicular pain.
Less Common Causes
Other, less frequent causes of unilateral testicular pain include
- Testicular tumors, which may initially present with dull discomfort or heaviness rather than acute pain.
- Chronic conditions such as idiopathic orchialgia, characterized by long-term testicular pain without a clearly identifiable cause.
- Systemic infections, including sexually transmitted infections without overt epididymitis.
Diagnostic Approach
Accurate diagnosis of unilateral testicular pain requires a systematic approach
History Taking
A thorough history should include the onset, duration, character, and severity of pain, as well as associated symptoms such as swelling, fever, urinary complaints, trauma, or sexual activity. Previous episodes, family history, and underlying medical conditions should also be documented.
Physical Examination
Examination involves inspection and palpation of the scrotum, testicles, epididymis, and spermatic cord. Key findings, such as high-riding testicle, tenderness, swelling, or abnormal mass, help narrow the differential diagnosis. Cremasteric reflex testing and transillumination may provide additional clues.
Imaging and Laboratory Tests
Scrotal ultrasound with Doppler flow is the gold standard for evaluating testicular blood flow, ruling out torsion, and assessing for epididymitis, hydrocele, or tumors. Urinalysis and urine cultures help identify infectious causes. In certain cases, blood tests, including inflammatory markers and hormone levels, may be indicated.
Treatment Considerations
Treatment depends on the underlying cause. Testicular torsion requires emergency surgery. Infectious causes such as epididymitis or orchitis are managed with antibiotics, analgesics, and supportive care. Trauma may necessitate observation, pain management, or surgical repair. Referred pain requires addressing the primary source. Patients with chronic or idiopathic pain may benefit from multidisciplinary approaches including urology, pain management, and psychological support.
When to Seek Immediate Medical Attention
Unilateral testicular pain should always be evaluated promptly. Immediate medical attention is critical if
- Pain is sudden, severe, or associated with nausea and vomiting
- There is swelling, redness, or tenderness of the testicle
- Previous episodes of testicular pain occur
- There is history of trauma or systemic symptoms such as fever
Unilateral testicular pain is a multifactorial condition with a wide differential diagnosis ranging from benign to life-threatening causes. Understanding the various possibilities, including testicular torsion, epididymitis, orchitis, hernias, trauma, and referred pain, is essential for timely and effective evaluation. Early recognition and prompt management, especially in acute cases, are crucial to preserving testicular function and overall health. Healthcare providers rely on careful history taking, physical examination, imaging, and laboratory investigations to determine the cause and guide appropriate treatment. Patients experiencing unilateral testicular pain should seek medical assessment without delay to ensure accurate diagnosis, prevent complications, and receive suitable care for long-term well-being.