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By Mayo Clinic staffA varicocele may cause:
- Shrinkage of the affected testicle (atrophy). The bulk of the testicle is made up of sperm-producing tubules. When damaged, as from varicocele, the testicle shrinks and softens. It's not clear what causes the testicle to shrink, but the malfunctioning valves allow blood to pool in the veins, which can result in increased pressure in the veins and exposure to toxins in the blood that may cause testicular damage.
- Infertility. It's not clear how varicoceles affect fertility. Some experts believe the testicular veins cool blood in the testicular artery, helping to maintain the proper temperature for optimal sperm production. By blocking blood flow, a varicocele may keep the temperature too high, affecting sperm formation and movement (motility).