Nearly 1 in 7 couples is infertile, which means they haven't been able to have a child after having sex often without protection for a year or longer. In up to half of these couples, male infertility is at least part of the reason.

Too few sperm, sperm that don't work well or blockages that keep sperm from going where they need to go can cause male infertility. Illnesses, injuries, long-term health conditions, lifestyle choices and other factors may be part of male infertility.

Not being able to have a child can cause you and your partner stress. But there are treatments for male infertility.

The main sign of male infertility is not being able to start a pregnancy. There may be no other symptoms.

When to see a doctor

See a healthcare professional if you haven't been able to cause pregnancy after a year of regular sex without protection or after six months if your partner is older than 35.

There are many causes of male infertility. Sometimes there's more than one cause.

The causes of infertility may involve any of the following. To get your partner pregnant, you need to:

• Make healthy sperm. This starts with the growth of the male reproductive organs during puberty. At least one of your testicles must work. And your body must make testosterone and other hormones to be able to make sperm.
• Have sperm that gets into the semen. Once the testicles make sperm, tubes carry them until they mix with semen. Ejaculation takes them out of the penis.
• Have enough sperm in the semen. If the number of sperm in your semen, called the sperm count, is low, it lowers the odds of one of your sperm fertilizing your partner's egg. A low sperm count is fewer than 15 million sperm per milliliter of semen or fewer than 39 million per ejaculate.
• Have sperm that works and moves. If your sperm doesn't move or work as it should, the sperm may not be able to reach your partner's egg or get inside it.

Medical causes

Health issues and medical treatments that can affect male fertility include:

• Varicocele. A varicocele is a swelling of the veins that drain the testicles. It's the most common cause of male infertility that can be fixed. Experts don't know exactly how varicoceles cause infertility, but it may be linked to blood flow that isn't typical. Varicoceles lead to lower sperm quantity and quality.

• Infection. Some infections can affect sperm making or sperm health or cause scarring that keeps sperm from traveling. These include epididymitis, irritation and swelling of the coiled tube at the back of the testicle, called the epididymis. Infections also include orchitis, irritation and swelling of one or both testicles, and some sexually transmitted infections, including gonorrhea or HIV.

  Some infections can cause lifelong damage to the testicles. But most often they can still make sperm.

• Ejaculation issues. Retrograde ejaculation is when semen enters the bladder during climax instead of coming out the tip of the penis. Conditions that can cause retrograde ejaculation include diabetes, spinal injuries, medicines, and surgery of the bladder, prostate or urethra.
• Antibodies that attack sperm. Antibodies are immune system cells that see sperm as harmful. The antibodies try to get rid of the sperm.
• Tumors. Cancers and tumors that aren't cancer can affect the male reproductive organs directly. This may be through the glands that release hormones related to reproduction, such as the pituitary gland, or through causes that aren't known. Sometimes, surgery, radiation or chemotherapy to treat tumors can affect male fertility.
• Testicles that don't come down from the belly. In some unborn males, one or both testicles fail to come down from the belly into the sac that holds the testicles, called the scrotum. This is likely to lower fertility.
• Hormone imbalances. Conditions of the testicles or conditions that affect other hormone systems can affect fertility. Other hormone systems include the hypothalamus, pituitary, thyroid and adrenal glands. There are a number of possible causes for low testosterone, called male hypogonadism, and other hormonal issues.

• Issues with the tubes that transport sperm. Many tubes carry sperm. They can be blocked due to damage from surgery, infections, injury or not forming right.

  Blockage can happen at any level. This includes within the testicle; in the coiled tube at the back of the testicle, called the epididymis; in a tube that carries semen from the testicles, called the vas deferens; near the ejaculatory ducts or in the tube that carries urine out of the body, called the urethra.

• Chromosome issues. Conditions passed through families, called inherited, can cause the male sex organs to not form well. One such condition is Klinefelter syndrome, in which a male is born with two X chromosomes instead of one and one Y chromosome. Another genetic syndrome linked with infertility is cystic fibrosis.
• Trouble having sex. These can include trouble getting or keeping an erection firm enough for sex, called erectile dysfunction (ED). Other issues include ejaculating too soon; painful sex; or a penis that isn't formed well. For instance, the opening of the urethra may be under the penis, called hypospadias. Mental and relationship issues also may be involved.
• Certain medicines. Some medicines can affect the making of sperm and lower male fertility. These include testosterone replacement therapy, anabolic steroids used long term, chemotherapy medicines, some ulcer medicines and some arthritis medicines.
• Surgeries. Certain surgeries may keep you from having sperm in your ejaculate. These include vasectomy, scrotal or testicular surgeries, prostate surgeries, and surgeries for testicular and rectal cancers, among others.

Causes in the environment

Being around certain elements such as heat, toxins and chemicals can cause you to make less sperm or keep the sperm from working well. Causes include:

• Industrial chemicals. Being around certain chemicals, pesticides, herbicides, organic solvents and painting products for a time may be part of low sperm counts.
• Heavy metal. Being around lead or other heavy metals also may cause infertility.
• Radiation or X-rays. Being around radiation can lessen sperm making, though it often returns to the usual amount in time. High doses of radiation can lessen sperm making long term.

• Heat on the testicles. High temperatures may harm sperm making and affect how sperm works. Some studies suggest that using saunas or hot tubs may lower sperm count for a time.

  Sitting or working on a laptop computer for long periods and wearing tight clothing also may raise the temperature in the scrotum. This may cut sperm making a bit. More research is needed.

Health, lifestyle and other causes

Some other causes of male infertility include:

• Drug use. Anabolic steroids taken to build muscle can cause the testicles to shrink and lower the sperm count. Use of cocaine or marijuana may cut the number and quality of sperm for a time.
• Alcohol use. Drinking alcohol can lower testosterone levels, cause ED and lower sperm count. Liver disease caused by too much drinking also may lead to fertility issues.
• Tobacco smoking. Smoking may lower sperm count. Secondhand smoke also may affect male fertility.
• Body weight. Having obesity can harm fertility. It can affect the sperm and cause hormone changes that lower male fertility.

Risk factors linked to male infertility include:

• Lifestyle choices that aren't healthy. This includes smoking and using alcohol and certain illicit drugs.
• Issues with the testicles, such as injury, having had a vasectomy or major belly or pelvic surgery, keeping the testicles too warm or having testicles that didn't come down from the belly into the scrotum.
• Having certain past or present infections.
• Being around toxins.
• Being born with a fertility condition or having a blood relative with a fertility condition.
• Having certain medical conditions, including obesity, tumors and long-term illnesses, such as sickle cell disease and celiac disease. Having sleep apnea or otherwise sleeping poorly also can affect sperm.
• Taking certain medicines or having medical treatments, such as surgery or radiation for treating cancer.

Complications of male infertility can include:

• Being stressed and having partner troubles linked to not being able to have a child.
• Needing costly and complex fertility treatments.
• Having a higher risk of cancer, including testicular cancer.

Male infertility isn't always preventable. But you can try to stay away from some known causes of male infertility. For instance:

• Don't smoke.
• Limit or don't drink alcohol.
• Don't use illicit drugs.
• Stay at a healthy weight.
• Don't do things that heat the testicles.
• Lower stress.
• Stay away from pesticides, heavy metals and other toxins.

Diagnosis of infertility often involves both partners. It might take some tests to find the cause of infertility. Sometimes, no cause is found.

Diagnosing male infertility issues most often involves:

• Physical exam and medical history. Besides looking at your genitals, your healthcare professional asks about any conditions that affect your family, long-term health conditions, injuries or surgeries that could affect fertility. Be ready to answer questions about your sex life, whether you've fathered children in the past, and about your puberty.

• Semen analysis. You can give a semen sample by masturbating and ejaculating into a special container at a medical office. Some people prefer using a special condom during sex at home to collect a sample.

  Your semen then goes to a lab to measure the number of sperm present and look for any issues with the sperms' shape, called morphology, and movement, called motility. The lab also checks your semen for signs of infection or other issues.

  Sperm counts often change from one sample to the next. So you may have several semen analysis tests done over time to make sure the results are correct. If your sperm analysis is typical, your healthcare professional may suggest testing your partner before you have any more tests.

Other tests can help find the cause of your infertility. These can include:

• Scrotal ultrasound. This test uses sound waves to make images inside your body. A scrotal ultrasound can show if there is a varicocele or other issues in the testicles or around them.
• Transrectal ultrasound. A healthcare professional puts a small, lubricated wand into the rectum to check your prostate and look for blockages of the tubes that carry semen.
• Hormone testing. Hormones that the pituitary gland, hypothalamus and testicles make are vital to fertility. Issues in other hormonal or organ systems also might be part of infertility. A blood test measures the level of testosterone and other hormones.
• Post-ejaculation urinalysis. Sperm in your urine can show that sperm are traveling backward into the bladder instead of out your penis during ejaculation. This is called retrograde ejaculation.
• Genetic tests. Changed genes can be a cause of very low sperm count. A blood test can show small changes in the Y chromosome. Genetic testing can diagnose conditions that were present at birth, called congenital, or passed through families, called inherited.
• Testicular biopsy. This test involves removing tissue samples from the testicle with a needle. If the results of the testicular biopsy show that you're making sperm as expected, you likely have a blockage or another issue with sperm getting to where it needs to go.

Often, healthcare professionals can't find the exact cause of infertility. But even without an exact cause, there may be treatments for you that lead to your partner getting pregnant.

For most couples, both partners need to be checked. There may be treatments your partner needs, as well. Or you may learn that certain treatments won't work for the two of you.

Treatments for male infertility include:

• Surgery. For instance, surgery often can correct a varicocele or repair a blocked vas deferens. Surgery can reverse vasectomies. When there are no sperm in the ejaculate, sperm retrieval surgery often can get sperm from the testicles, epididymis or bladder in people whose sperm goes into the bladder instead of out the penis.
• Treating infections. Antibiotic treatment may cure an infection of the reproductive tract. But it doesn't always bring fertility back.
• Treatments for issues with having sex. Medicines or counseling can help conditions that affect fertility, such as ED or ejaculating too soon.
• Hormone treatments and medicines. Hormone replacement or medicines might help with infertility caused by high or low levels of certain hormones or issues with the way the body uses hormones.

• Assisted reproductive technology (ART). ART treatments involve getting sperm through ejaculation, surgery or from a donor. A healthcare professional then puts the sperm into the female partner.

  A healthcare professional also can mix the sperm with an egg in a lab, called in vitro fertilization. Or a healthcare professional can put a sperm into an egg, called intracytoplasmic sperm injection.

When treatment doesn't work

Rarely, there's no treatment for male fertility problems. For you to have a child, your healthcare professional might suggest that you and your partner think about using sperm from a donor or adopting a child.

There are a few steps you can take at home to increase your chances of causing pregnancy:

• Have sex more often. Having sex every day or every other day beginning at least five days before your partner releases an egg, called ovulation, raises your chances of getting your partner pregnant.
• Time your sex. Pregnancy is most likely when the female releases an egg, called ovulation. This happens in the middle of the menstrual cycle, between periods. Sperm can live for a few days. So have sex 5 to 7 days before the date of ovulation and until two days after ovulation.
• Don't use lubricants. Products such as Astroglide or K-Y jelly, lotions, and spit might keep sperm from moving and working as they should. Ask your healthcare professional about sperm-safe ways to make the vagina moist.
• Live a healthy lifestyle. Eat healthy foods, stay at a healthy weight, get enough sleep, and exercise most days.
• Don't do things that harm health. Stop or limit your use of alcohol, quit smoking, and don't use illicit drugs.

Some studies show that the following herbs or supplements may help male fertility by improving sperm count or quality.

• Coenzyme Q10.
• Folic acid and zinc combined.
• L-carnitine.
• Selenium.
• Vitamin C.
• Vitamin E.

Talk with your healthcare professional before taking dietary supplements for male infertility. There's no good proof that they work, and some supplements may cause side effects or affect other medicines you take.

Coping with infertility can be hard. You can't know how long it will last or what the outcome will be. It brings up many feelings for couples. Plans for coping may help.

Planning for ups and downs

• Set limits. Fertility treatments can be costly and often insurance doesn't cover them. Decide as a couple how many and what kind of procedures you think you can handle. How much are you willing to spend? Talk about how you'll deal with the feelings the process brings up.
• Take a break. Sometimes it may help to stop treatment for a few months, then try again.
• Think about other choices. What else might you do? Use a donor sperm or egg? Adopt? Thinking about this early in the process may relieve some of the worry during treatments and help with loss of hope if treatments don't work.
• Talk about your feelings. Find support groups or counseling services for help before and after treatment. These may help you get through the process and help with grief if treatment fails.

Managing stress during treatment

• Try ways to reduce stress. These might include yoga, meditation, deep breathing or massage therapy.
• Think about getting counseling. Counseling such as cognitive behavioral therapy might help you relax and manage stress.
• Talk to others. Reach out to others rather than holding in the feelings the process brings up.
• Stay in touch with loved ones. Talking to your partner, family and friends can be helpful.

You might start by seeing your main healthcare professional. If you have a known condition that causes infertility or have had tests that showed fertility issues, your healthcare professional may send you to a specialist.

Here's some information to help you get ready for your appointment.

What you can do

• Ask what you need to do before the appointment. For instance, if you're having a semen analysis, don't ejaculate for at least 2 to 5 days before it's time to collect the sperm.
• Take your partner with you. Your partner also may need tests to check for fertility issues. And your partner can help keep track of information your healthcare professional gives you or have questions you may not think of.
• Find out what your medical plan covers before you have infertility tests. Infertility tests can be costly, and your insurance may not cover them.

Make a list of:

• All medicines, vitamins and supplements you take and their dosages. This includes muscle-building substances and alcohol, tobacco, marijuana or other illicit drugs.
• Male family members who had fertility issues. This includes brothers or fathers.
• Write down questions to ask your healthcare professional.

Questions to ask your doctor

Basic questions to ask include:

• What might be causing my infertility?
• Other than the most likely cause, what are other possible reasons my partner and I haven't been able to have a child?
• What tests do I need?
• Will my partner also need tests?
• What treatments are there for my condition?
• Should I see a specialist?
• Are there brochures or fact sheets that I can have? What websites do you suggest?

Be sure to ask all the questions you have.

What to expect from your doctor

Be ready to answer questions such as:

• At what age did you start puberty?
• Have you had issues with sex with this partner, such as trouble getting and keeping an erection, ejaculating too soon, or not being able to ejaculate?
• Have you ever fathered a child?
• Have you had a vasectomy or other belly, pelvic or scrotal surgery?