The most common sign of infertility is simply not getting pregnant after consistent, unprotected sex for 12 months (or 6 months if you’re over 35). About 15% of couples experience this. But your body often gives earlier clues that something may be affecting your fertility, and many of these signs show up long before you start trying to conceive.
Some signs are obvious, like missing periods. Others are subtler, like changes in your skin or hair that hint at a hormonal imbalance. Here’s what to watch for in both women and men.
Irregular or Missing Periods
This is the single most telling sign of female infertility. A cycle shorter than 21 days, longer than 35 days, or one that’s unpredictable from month to month often means you’re not ovulating regularly. No ovulation means no egg available for fertilization. Periods that disappear entirely are an even stronger signal.
Heavy periods matter too. Soaking through a pad or tampon every hour, passing large clots, or bleeding for more than seven days can point to conditions like fibroids or endometriosis that interfere with conception. On the other end, very light or unusually short periods can indicate that the uterine lining isn’t developing enough to support a pregnancy.
Painful Periods and Pelvic Pain
Some cramping during your period is normal. Pain that’s severe enough to interfere with your daily life, or pelvic pain that shows up between periods or during sex, is not. This kind of pain is a hallmark of endometriosis, a condition where tissue similar to the uterine lining grows in places it shouldn’t, like on your ovaries, fallopian tubes, or other pelvic structures. Endometriosis can cause scarring and inflammation that physically block or damage the reproductive organs.
Skin and Hair Changes
Your skin and hair are surprisingly good windows into your hormonal health. In women, persistent acne on the face, chest, or upper back, combined with new or worsening facial hair growth, often points to excess androgens (sometimes called “male hormones,” though all bodies produce them). Up to 70% of women with polycystic ovary syndrome (PCOS) experience this kind of unwanted hair growth on the face, arms, chest, or abdomen. PCOS is the most common cause of female infertility.
Other PCOS-related signs include thinning hair on the scalp and patches of darkened skin in body folds like the neck, armpits, and groin. Weight gain that’s difficult to manage is also common: between 40% and 80% of women with PCOS struggle with obesity.
In men, decreased facial or body hair can signal low testosterone or other hormonal problems that reduce sperm production. Unexpected breast tissue growth is another hormonal red flag.
Signs of Male Infertility
Male factors contribute to roughly half of all infertility cases, yet many men assume the issue lies elsewhere. The physical signs in men are different from women’s and can be easy to overlook or dismiss.
Problems with sexual function are the most noticeable category. This includes difficulty maintaining an erection, reduced sex drive, trouble with ejaculation, or noticeably small volumes of fluid during ejaculation. Any of these can indicate hormonal imbalances or structural problems that affect fertility.
Pain, swelling, or a lump in the testicle area deserves attention regardless of whether you’re trying to conceive. Varicoceles (swollen veins in the scrotum) are one of the most common treatable causes of male infertility, and they often show up as a dull ache or visible swelling. Less commonly, recurrent respiratory infections paired with an inability to smell can indicate a rare genetic condition that also causes infertility.
Age-Related Fertility Decline
Age isn’t a “sign” you can observe, but it’s the single biggest factor in fertility for women. Egg quantity and quality begin declining in the early 30s and drop more steeply after 35. This is why the clinical threshold for seeking help shifts from 12 months of trying to just 6 months for women over 35.
Men’s fertility also declines with age, though more gradually. Sperm quality, including how well sperm move and whether they’re shaped normally, tends to decrease after 40. The decline is less dramatic than in women, but it’s real.
Lifestyle Factors That Raise Risk
Certain habits don’t cause obvious physical symptoms but quietly erode fertility in both sexes. Smoking is one of the biggest offenders. Roughly one in five men and women of reproductive age in the U.S. smoke, and cigarette smoke has substantial harmful effects on the ability to conceive, though many smokers aren’t aware of this connection. Smoking damages egg and sperm quality, disrupts hormone levels, and in women can accelerate the natural decline in egg supply.
Being significantly overweight or underweight also affects fertility. Excess body fat can throw off the hormonal balance needed for regular ovulation, while too little body fat can shut ovulation down entirely. In men, obesity is linked to lower sperm counts and reduced testosterone. Heavy alcohol use and chronic stress compound these effects in both partners.
What Testing Looks Like
If you recognize several of these signs, or if you’ve been trying to conceive without success, testing is straightforward for both partners. For women, the initial workup typically involves blood tests to check hormone levels related to ovulation and egg supply, along with imaging to look at the uterus and fallopian tubes.
For men, the starting point is a semen analysis. This measures sperm count (normal is 15 million or more per milliliter), how well the sperm swim (at least 40% should be moving), and what percentage have a normal shape (4% or higher is considered within range). The test is simple and noninvasive, and results come back quickly. Because male-factor issues are so common and so easy to screen for, testing both partners early saves time.
About 13.4% of women ages 15 to 49 in the U.S. have impaired fertility, and nearly 14% of women ages 20 to 49 have used some form of fertility services. These numbers reflect how common fertility challenges are, and how routinely they’re addressed in medicine today. Many of the underlying causes, from PCOS to hormonal imbalances to low sperm count, respond well to treatment once they’re identified.