What Causes Male Infertility?

Hillary Bennetts

What Causes Male Infertility?

Table of contents

  • What is male infertility?
  • What happens if a Man is Infertile?
  • How Common is Infertility in Men?
  • Who is at Risk for Male Infertility?
  • Symptoms of infertility in Men
  • Causes of Male Infertility
  • Can You Fix Male Infertility?
  • Can Male Infertility be Prevented?

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There are many causes of infertility. Let’s take a look at some of the factors that can cause infertility in men, and what we can do to support them. 

What is male infertility?

Infertility is a disease of the male or female reproductive system defined by the failure to achieve a pregnancy after 12 months or more of regular unprotected sex.

Specifically, male infertility is a condition that affects people assigned male at birth and is most often due to problems with a man’s sperm production or sperm health.

What happens if a man is infertile?

If a man is infertile, he is unable to make a fertile female pregnant after a minimum of one year of regular unprotected intercourse. 

How common is infertility in men?

A report published by the World Health Organization (WHO) found that roughly 1 in 6 adults worldwide (about 17.5% of the adult population) experience infertility. 

Interestingly, the estimates show that there isn’t much difference in rates of infertility between high-, middle- and low-income countries. Lifetime prevalence was 17.8% in high-income countries and 16.5% in low- and middle-income countries.

It is estimated that males are solely responsible for about 20% of cases and is a contributing factor in another 30% to 40% of all infertility cases. Overall, the male factor substantially contributes to about 50% of all cases of infertility.

Who is at risk for male infertility?

There is not always a cause of male infertility but there are certain factors that may make a person more likely to have male infertility. These include the following:

  • Past inflammation of the prostate or past genital infections
  • Injury to or twisting (torsion) of the testicles
  • Early or late puberty
  • Exposure of the genitals to high temperatures
  • Prior hernia repair
  • Having undescended testicles
  • Use of certain prescription medicines, like those for ulcers, psoriasis, depression, and high blood pressure.

Symptoms of infertility in men

The primary (and most obvious) sign of male infertility is the inability to conceive a child. However, in some cases, an underlying problem such as an inherited disorder, hormonal imbalance, dilated veins around the testicle, or a condition that blocks the passage of sperm can cause additional signs and symptoms, such as the following:

  • Problems with sexual function (e.g., difficulty with ejaculation or small volumes of fluid ejaculated, reduced libido, or erectile dysfunction)
  • Pain, swelling, or a lump in the testicular area
  • Recurrent respiratory infections
  • Loss of smell
  • Abnormal breast growth (gynecomastia)
  • Decreased facial or body hair 

Causes of male infertility

Conception is a complex process, there are so many things that must happen in order to result in a pregnancy. Some of the factors that are influenced by male fertility include the following: 

  • He must produce healthy sperm. This goes back to the growth and formation of the male reproductive organs early in life. At least one of the testicles must be functioning correctly, and the body must produce testosterone and other hormones for proper sperm production.
  • Sperm must be carried into the semen. Once sperm is produced in the testicles, they must be transported into the semen so that they exist in ejaculate.
  • There must be enough sperm in the semen. The more sperm that are in semen, the more likely it is that one will fertilize an egg. A low sperm count is considered to be fewer than 15 million sperm per milliliter of semen or fewer than 39 million per ejaculate.
  • Sperm must be functional and able to move. Sperm must be able to reach and penetrate an egg, so they must be healthy and motile. 

Most of the causes of male infertility result from one or more of these items not working as needed. 

Medical causes

Male infertility can be caused by a number of health issues and medical treatments. These may include the following:

  • Varicocele: A varicocele is a swelling of the veins that drain the testicle. Varicoceles lead to reduced sperm quantity and quality and are the most common reversible cause of male infertility.
  • Infection: Certain infections can interfere with sperm production or sperm health or can cause scarring that blocks sperm from entering semen. 
  • Ejaculation issues: Retrograde ejaculation occurs when semen enters the bladder during orgasm instead of exiting out the tip of the penis. Retrograde ejaculation can result from other health conditions or from taking certain medications.
  • Immunologic antibodies: In some cases, the immune system produces antibodies that kill their own sperm.
  • Tumors: Cancerous and nonmalignant tumors can affect male reproductive organs. Surgery, radiation, or chemotherapy to treat tumors can also affect male fertility.
  • Undescended testicles: Sometimes, one or both testicles fail to descend from the abdomen into the scrotum during fetal development. Men with undescended testicles, especially if not addressed early, may face infertility.
  • Hormone imbalances: Infertility can result from imbalances in various hormones that involve the sex hormones, or the hypothalamus, pituitary, thyroid, and adrenal glands. 
  • Defects of tubules that transport sperm: The many different tubes that carry sperm can be blocked for a variety of reasons, including injury from surgery, prior infections, trauma, or abnormal development.
  • Chromosome defects: Inherited disorders such as Klinefelter's syndrome can cause abnormal development of the male reproductive organs. Other genetic conditions  associated with infertility include cystic fibrosis and Kallmann's syndrome.
  • Prior surgeries: Certain surgeries that involve the scrotum, testicles, prostate, or abdomen, or intestines may impact fertility.

Environmental toxins

Overexposure to certain environmental elements can reduce sperm production or affect sperm function. These may include the following:

  • Hormone disrupting chemicals: Repeated exposure to certain chemicals may affect sperm health. These can be found in things like paint and pesticides, but also in everyday personal care and cleaning products. 
  • Heavy metal exposure: Exposure to lead or other heavy metals may impact sperm health.

Health, lifestyle and other causes

Lifestyle factors may also contribute to male infertility: 

  • Drug use: Anabolic steroids taken to stimulate muscle strength and growth, and use of nonprescription drugs like cocaine or marijuana may temporarily reduce the number and quality of sperm
  • Alcohol use: Chronic alcohol consumption has been associated with poor semen quality. 
  • Tobacco smoking: Smoking can impact sperm count and quality
  • Weight: Obesity can impact reproductive hormone levels in men, which can in turn impact sperm production.

Can you fix male infertility?

While some cases of infertility are unexplained or cannot be resolved, other cases of infertility can be addressed by lifestyle changes or other interventions with a healthcare practitioner.

Lifestyle changes

The good news is that certain lifestyle changes can positively impact sperm count and quality. 

  • Maintaining a healthy weight 
  • Focusing the diet on whole foods and healthy fats
  • Engaging in regular physical activity
  • Stopping smoking, drinking, and using recreational/nonprescription drugs.
  • Limiting exposure to environmental toxins.
  • Taking vitamins and supplements to support fertility, like Needed’s Sperm Support+, CoQ10, and other men’s fertility supplements.


Since certain medications can impact sperm health and fertility, you may discuss temporarily pausing, or finding an alternative to these medications.


Surgical treatments are not common, but may include the following:

  • Vasoepididymostomy: This surgery removes a blockage in the tube that lies against the testicle where sperm mature (the epididymis).
  • Sperm retrieval: A healthcare provider can perform a biopsy to retrieve sperm from the testicles or epididymis.
  • Varicocelectomy: A varicocele is a condition that causes pooling of blood in the testicles due to varicose veins in the scrotum. Surgery helps to resolve the varicose veins.

Assisted reproductive technology

Assisted reproductive technology (ART) can help in cases where sperm needs support to meet an egg. In Vitro Fertilization (IVF) is an example of how ART can help produce a pregnancy.

Can male infertility be prevented?

Male infertility cannot always be prevented. However, you may be able to reduce your risk of male infertility by making certain lifestyle choices:

  • Avoid smoking, drinking, and nonprescription drugs.
  • Limit exposure to hazardous chemicals, like hormone disruptors found in many personal care and cleaning products.
  • Do not expose the testicles to direct heat for long periods of time
  • Maintain a healthy weight 
  • Engage in regular physical activity
  • Eat a diet rich in whole foods and healthy fats
  • Take targeted fertility supplements to support sperm health.

Fertility can feel overwhelming and frustrating, but doing what you can to support fertility can help to empower you along your journey to parenthood.

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Hillary Bennetts, Nutritionist

Hillary Bennetts is a nutritionist and business consultant focusing on prenatal and postpartum health. In addition to nutrition consulting, she provides business consulting and content creation for companies in the health and wellness industry. Hillary spent almost a decade in corporate consulting before shifting gears to combine her lifelong passion for health and wellness with her business background and nutrition education.