The short answer
Testicular cancer risk is linked to an undescended testicle, abnormal testicle development, personal or family history, and Klinefelter syndrome. Having a risk factor does not mean testicular cancer is certain.
An undescended testicle (cryptorchidism) is one of the strongest known risk factors.
A personal or family history of testicular cancer raises risk.
Klinefelter syndrome, a genetic condition, raises risk.
Testicular cancer is more common in White men than in men of other races.
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The full explanation.
The simple version
Testicular cancer has a small number of known risk factors. Most relate to how the testicles developed, or to genetics. Many people diagnosed have no known risk factor at all.
Having a risk factor does not mean testicular cancer is certain, and it is not something anyone does to themselves.
Known risk factors
- Undescended testicle (cryptorchidism). A testicle that did not move down into the scrotum before birth raises risk. That stays true years after surgery to correct it. It applies to the testicle that descended normally too.
- Abnormal testicle development. A testicle that is smaller than normal, or does not work as it should, raises risk.
- Testicular carcinoma in situ. Abnormal cells sit in the testicle but are not yet invasive cancer. They raise the risk of cancer later, so the care team watches them closely.
- Personal or family history. A past testicular cancer raises risk. So does testicular cancer in a father or brother.
- Klinefelter syndrome. A genetic condition involving an extra X chromosome, linked to higher risk.
- Race. Testicular cancer is more common among White men than among men of other racial or ethnic groups.
In short: how the testicles developed, family history, and certain genetic conditions are the known factors.
This is not something you caused
The known risk factors are things like early development and genetics. There is no evidence that injury, exercise, or bike riding causes testicular cancer. If you are living with this diagnosis, the cause was outside your control.
Why this matters for you
If you had an undescended testicle or a family history, your care team may watch the other testicle more closely. Most testicular cancers can be cured, even when found at an advanced stage. So knowing your risk factors is about informed follow-up, not fear.
What to watch for
Risk factors matter most when they lead you to report a change early. NCI lists these as reasons to check with a doctor:
- A painless lump or swelling in either testicle.
- A change in how a testicle feels.
- A dull ache in the lower belly or the groin.
- A sudden build-up of fluid in the scrotum.
When to get help sooner
- Call 911 or go to an emergency department if you have sudden, severe pain in a testicle or the scrotum, especially with nausea or vomiting.
- Call your care team the same day if a testicle turns red, hot, or swollen over a few hours.
- Call your care team within a day or two if you find a new painless lump or firm area in a testicle, or a dull groin ache that does not settle.
Sources
Words to know
Tap any term to see what it means.
Common questions
What is an undescended testicle and why does it matter?
Before birth, testicles normally move down into the scrotum. When one does not, it is called an undescended testicle or cryptorchidism. This raises the risk of testicular cancer, even if it was surgically corrected in childhood, and the risk applies to both testicles.
Can testicular cancer run in families?
Yes. Having a father or brother who had testicular cancer raises your own risk, though most men diagnosed have no family history.
Is testicular cancer linked to injury or activity, like sports or bike riding?
No. There is no evidence that injury, exercise, or activities like bike riding cause testicular cancer. This is a common myth.
Did I do something to cause my testicular cancer?
No. Testicular cancer largely stems from factors present from before birth, such as testicular development, or from genetics. It is not caused by lifestyle choices, injury, or anything you did.
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Last updated: 2026-08-11Next planned review: 2027-08-03
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How this page was created
Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes. We do not employ clinicians and do not intend to — our work is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
Editorial status: Source checked — This page was written with AI assistance and checked line by line against the sources listed on it. That confirms the sources support what the page says. It is not a medical review, and it does not confirm the page is complete or right for your situation.
Human medical review: not completed. Pages here are not signed off by a clinician before they publish. That is not an oversight we are quietly working around: we restate published guidance and cite it, so the authority belongs to the source rather than to us, and every page names where its claims come from — you can verify us instead of trusting us. Where a volunteer clinician has reviewed a page, their name and credentials appear on it; where no name appears, no clinician has checked it. We are glad to have reviewers and are recruiting them, and we do not hold pages back waiting for one. Use this site to understand your situation and to ask better questions of the people treating you.
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