One Testicle Larger Than the Other: When That Is Normal

It’s common for men to notice that one testicle is a bit bigger or hangs lower than the other. In most cases, this “one testicle larger than the other” situation is harmless. Testicular asymmetry is a normal part of male anatomy, much like having one hand slightly larger than the other. This guide explains when size differences are routine, what to watch for, and when to get checked by a professional.

Why Testicles Differ in Size

Testicles develop independently inside the scrotum, so it’s natural for one to be:

• Slightly larger in volume
• A bit higher or lower
• Longer or a different shape

According to experts at the Mayo Clinic and the Cleveland Clinic, up to 80% of men will have noticeable asymmetry. Usually, the left testicle hangs lower and may appear bigger—this is normal.

Common Causes of Normal Variation

1. Developmental Differences
   • Testicles descend into the scrotum before birth. If one descends earlier or along a slightly different path, it may grow to a different size.
2. Blood Flow Variations
   • Slight differences in blood vessel size and orientation can create mild size asymmetry without any health risk.
3. Scrotal Anatomy
   • The membrane (tunica vaginalis) around each testicle can hold differing amounts of fluid, causing one sac to bulge more.

When “One Testicle Larger Than the Other” Is Still Normal

You don’t need to worry if:

• The difference is less than 20–25% in volume.
• There’s no pain, discomfort, or heaviness.
• Both testicles feel firm but not hard or rock-like.
• The surface is smooth, with no distinct lumps.
• The size difference has been consistent for months or years.

If you tick all these boxes, you’re likely experiencing normal variation.

Signs to Watch For

Even though minor asymmetry is typical, certain changes call for attention. Seek medical advice if you notice:

• Sudden increase in size on one side
• New or growing lumps
• Persistent ache or sharp pain
• Swelling that doesn’t go down
• A feeling of heaviness or dragging in the scrotum
• Redness, warmth, or fever

These symptoms could suggest conditions that need treatment, such as epididymitis, hydrocele, varicocele, or, rarely, testicular cancer.

Possible Underlying Conditions

If “one testicle larger than the other” appears with worrisome signs, these are some possibilities:

• Hydrocele
  Fluid buildup around the testicle causing a soft, painless swelling.
• Varicocele
  Enlarged veins above the testicle producing a “bag of worms” sensation.
• Epididymitis
  Inflammation of the tube at the back of the testicle, often with pain and fever.
• Inguinal Hernia
  Part of the intestine pushes into the scrotum, sometimes causing pain or bulging.
• Testicular Torsion
  Twisting of the testicle’s blood supply, leading to sudden, severe pain—a medical emergency.
• Testicular Cancer
  Presents as a painless lump or swelling; early detection greatly improves outcomes.

At-Home Check: How to Perform a Self-Exam

Regular self-exams help you recognize what’s normal for you. The American Urological Association recommends:

1. Perform exams after a warm bath or shower (the scrotum is relaxed).
2. Roll each testicle gently between your thumb and fingers.
3. Feel for any lumps, bumps, or hard spots.
4. Compare both sides—take note of any differences in size, shape, or texture.
5. If anything seems unusual, jot down what you find and when.

Free Symptom Check Option

If you’re unsure about any symptom, you might consider doing a free, online symptom check, using the doctor approved Ubie Symptom Checker. It’s a quick way to get guidance on whether you need in-person evaluation.

When to See a Healthcare Provider

Book an appointment if you have:

• Persistent pain or discomfort
• Noticeable swelling or lumps
• Redness, warmth, or signs of infection
• Any sudden change in size or position

Your doctor will likely:

• Take a medical history and ask about symptoms
• Perform a physical exam of the scrotum
• Order an ultrasound to look at blood flow and structure
• Run blood tests for infection or tumor markers (if needed)

Treatment Options

Treatment varies depending on the cause:

• Hydrocele
  Often monitored; surgery if it’s large or uncomfortable.
• Varicocele
  May require surgery or embolization if it causes pain or fertility issues.
• Epididymitis
  Treated with antibiotics, rest, and scrotal support.
• Inguinal Hernia
  Surgery to repair the hernia.
• Testicular Torsion
  Immediate surgical untwisting is critical—delay can cause loss of the testicle.
• Testicular Cancer
  Early surgery, possibly followed by chemotherapy or radiation.

Preventive Tips

• Wear supportive underwear during sports.
• Avoid tight pants that restrict blood flow.
• Practice self-exams monthly.
• Follow up on any concerns promptly—early care often means simpler treatment.

Key Takeaways

• “One testicle larger than the other” is usually normal.
• Up to 80% of men have some asymmetry; the left side often hangs lower.
• Monitor for pain, lumps, swelling, or rapid changes.
• Use the Ubie Symptom Checker for a free, online symptom assessment.
• See a doctor if you have any worrisome signs—early evaluation is crucial.

This information is based on trusted medical sources, including the Mayo Clinic, the American Urological Association, and the Cleveland Clinic. Always speak to a healthcare professional about anything that could be life-threatening or serious.