Varicocele - Symptoms and Causes

What is a varicocele?

Testis including small veins

A varicocele is a collection of enlarged (dilated) veins (blood vessels) in the scrotum. It occurs next to and above one testicle (testis) or both testes (testicles).

The affected veins are those that travel in the spermatic cord. The spermatic cord is like a tube that goes from each testis up towards the lower tummy (abdomen). You can feel the spermatic cord above each testis in the upper part of the scrotum. The spermatic cord contains the tube that carries sperm from the testes to the penis (the vas deferens), blood vessels, lymphatic vessels and nerves.

Normally, you cannot see or feel the veins in the spermatic cord that carry the blood from the testicles. If you have a varicocele, the veins become bigger (they dilate) and this makes them more noticeable. It is similar to varicose veins of the legs. The size of a varicocele can vary. A large varicocele is sometimes said to look and feel like a bag of worms in the scrotum.

What causes a varicocele?

Normal vein valves

In most cases, the reason why the veins (blood vessels) become larger is because the valves of the small veins in the scrotum do not function well. There are one-way valves at intervals along the veins. The valves open to allow blood to flow towards the heart, but close when blood flow slows to stop blood flowing backwards.

If these valves do not work well, blood can flow backwards (due to gravity) and pool in the lower parts of the vein to form a varicocele. (This is similar to how varicose veins form in legs.)

It is not clear why the valves do not work well.

Abnormal vein valves

A varicocele may (rarely) develop if there is a blockage of larger veins higher in the tummy (abdomen). This puts back-pressure on the smaller veins in the scrotum which then enlarge (dilate). This is only likely to occur in men older than 40. For example, if a varicocele suddenly develops in an older man, it may indicate a tumour of the kidney has developed which is pressing on veins.

It must be stressed, the vast majority of varicoceles develop in teenagers and young men and are not due to a serious condition.

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  • Guidelines on Male Infertility; European Association of Urology (2015)
  • D'Andrea S, Micillo A, Barbonetti A, et al; Determination of spermatic vein reflux after varicocele repair helps to define the efficacy of treatment in improving sperm parameters of subfertile men. J Endocrinol Invest. 2017 May 25. doi: 10.1007/s40618-017-0695-x.
  • Kolon TF; Evaluation and Management of the Adolescent Varicocele. J Urol. 2015 Nov 194(5):1194-201. doi: 10.1016/j.juro.2015.06.079. Epub 2015 Jun 25.
Author:
Dr Laurence Knott
Peer Reviewer:
Dr Helen Huins
Document ID:
4379 (v41)
Last Checked:
07 July 2017
Next Review:
06 July 2020

Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. Patient Platform Limited has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.