Most guys don’t think about fertility until they’re trying to start a family. That’s normal. But the reality is that male factor infertility contributes to about half of all couple infertility cases, and the signs often show up long before you’re ready to conceive. The trick is knowing what to look for.
Here is what the research says about the early indicators, what they mean, and what you can do about them.
The Obvious One: Problems with Ejaculation or Erection
This is the most straightforward sign, and it’s often the one that gets men to finally see a doctor.
What to watch for:
- Low semen volume (less than about 1.5 milliliters per ejaculation)
- Difficulty achieving or maintaining an erection
- Pain or discomfort during ejaculation
- Retrograde ejaculation (semen going into the bladder instead of out the penis, which often presents as “dry” orgasms)
A 2023 review in Fertility and Sterility found that erectile dysfunction is associated with a 1.5 to 2 times higher risk of underlying fertility issues, because both conditions often share root causes-poor blood flow, hormone imbalances, or nerve damage.
What to do: If you notice any of these lasting more than a few weeks, that is a conversation worth having with your primary care doctor or a urologist. Not a “wait and see” situation.
Changes in Testicular Health
Your testicles are the factory. If the factory looks or feels different, the product might be off.
What to watch for:
- A lump or swelling in one testicle
- A feeling of heaviness in the scrotum
- Dull ache in the lower abdomen or groin
- One testicle noticeably smaller than the other (some asymmetry is normal, but a sudden change is not)
- Varicocele-a collection of enlarged veins in the scrotum that feels like a “bag of worms.” This is the most common reversible cause of male infertility, affecting about 15% of all men and up to 40% of men with primary infertility (Jarow et al., Journal of Urology, 1996).
What to do: Self-exams are simple and take 30 seconds in the shower. If you feel anything unusual, see a urologist. Varicoceles can often be surgically repaired, and sperm parameters improve in about 70% of men after treatment.
Unexplained Changes in Body Composition or Energy
Your hormones run on a feedback loop. When something is off, your body sends signals.
What to watch for:
- Unexplained weight gain, especially around the midsection
- Loss of muscle mass or strength despite consistent training
- Persistent fatigue that doesn’t improve with sleep
- Reduced libido (loss of interest in sex that is new for you)
These are often signs of low testosterone, but not always. A 2020 study in The Journal of Clinical Endocrinology & Metabolism found that men with infertility were significantly more likely to have metabolic syndrome (a cluster of conditions including abdominal obesity and insulin resistance) compared to fertile controls. The relationship goes both ways-poor metabolic health hurts sperm, and poor sperm quality can be a marker of broader metabolic issues.
What to do: If you’ve been sleeping 7 to 8 hours, training consistently, eating reasonably well, and still feel like you’re running on low battery for more than a month, get your hormones checked. A simple blood panel can tell you a lot.
Chronic Health Conditions That Fly Under the Radar
Some conditions don’t feel like “fertility problems” until you look under the hood.
What to watch for:
- Frequent respiratory infections or slow wound healing (can point to immune dysfunction or underlying inflammation)
- History of testicular trauma, infection (like mumps after puberty), or chemotherapy
- Undescended testicle(s) at birth, even if surgically corrected in childhood
- Long-term use of anabolic steroids or testosterone replacement therapy (these shut down natural sperm production, often for months after stopping)
What to do: If you have any of these in your medical history, it is worth mentioning to your doctor even if you are not trying to conceive. Some of these are time-sensitive. For example, if you’ve been on testosterone therapy and want to preserve fertility, there are alternatives (like clomiphene citrate or HCG) that your doctor can discuss.
The Numbers That Matter
Fertility is not binary. It is a spectrum. But here are some concrete numbers from the World Health Organization’s 2021 guidelines for semen analysis:
- Sperm concentration: Below 15 million per milliliter is considered low
- Total sperm count: Below 39 million per ejaculate is considered low
- Motility (movement): Less than 40% of sperm moving is considered low
- Morphology (shape): Less than 4% normal forms is considered low
These numbers are not pass/fail. Many men with counts below these thresholds still conceive naturally. But they are useful benchmarks.
What to do: If you are concerned, a semen analysis is the single most informative test. It is non-invasive, widely available, and usually covered by insurance if ordered by a doctor. Do not rely on at-home kits that only measure count. You need motility and morphology too.
When to Actually See a Doctor
Here is a practical guideline: If you and your partner have been having regular, unprotected intercourse for 12 months (or 6 months if your partner is over 35) without conception, both of you should be evaluated.
But you do not have to wait for that timeline if you notice any of the signs above. Early detection matters. A 2019 study in Human Reproduction Update found that men who sought evaluation for infertility earlier had better outcomes, because many causes (varicocele, hormonal imbalances, lifestyle factors) are treatable.
One sentence to remember: Fertility problems in young men are common, often silent, and frequently reversible. The earlier you catch them, the more options you have.
What You Can Take Away
You do not need to obsess over every twinge or tired day. But if you notice persistent changes in your sexual function, testicular appearance, energy levels, or body composition, pay attention. Your body is trying to tell you something. Listen to it, and then talk to a doctor who actually listens back.
Research cited:
- Jarow et al., “Varicocele and male infertility,” Journal of Urology, 1996
- WHO Laboratory Manual for the Examination and Processing of Human Semen, 6th edition, 2021
- Human Reproduction Update, “Time to pregnancy and male infertility evaluation,” 2019
- The Journal of Clinical Endocrinology & Metabolism, “Metabolic syndrome and male infertility,” 2020
- Fertility and Sterility, “Erectile dysfunction and infertility risk,” 2023