A low sperm count means there is less sperm than is typical in fluid called semen that the penis releases during orgasm.

A low sperm count also is called oligospermia (ol-ih-go-SPUR-me-uh). A complete lack of sperm is called azoospermia (ay-zoh-uh-SPUR-me-uh). Your sperm count is considered lower than typical if you have fewer than 15 million sperm per milliliter of semen.

Having a low sperm count makes it less likely that one of your sperm will join with your partner's egg to start a pregnancy. If needed, there are treatments to help couples boost their chances of becoming pregnant.

The main symptom of a low sperm count is not being able to start a pregnancy. There might be no other clear symptoms.

In some people, an underlying health condition causes a low sperm count along with other symptoms. Depending on the condition, these other symptoms can include:

• Trouble with sexual function — for example, some people have low sex drive. Others have trouble getting or keeping an erection that's firm enough for sex, also called erectile dysfunction.
• Pain, swelling or a lump in the testicle area.
• Less facial or body hair or other symptoms of a chromosome or hormone condition.

When to see a doctor

See a healthcare professional if you and your partner haven't been able to become pregnant after a year of regular sex without using birth control. This is how the condition known as infertility is defined. Get a healthcare checkup sooner if you have any of the following:

• Erection or ejaculation concerns, low sex drive, or other troubles having sex.
• Pain, discomfort, a lump or swelling in the testicle area.
• A history of testicle, prostate or sexual problems.
• Groin, testicle, penis or scrotum surgery.

For the body to make sperm, the testicles and certain organs in the brain that produce hormones need to work properly. Once sperm are made in the testicles, sperm travel in delicate tubes until they mix with semen. Then semen is released from the penis, usually during an orgasm. Issues with any of these systems can lower the number of sperm in semen.

When sperm's movement or shape is irregular, that also can lessen fertility.

Still, the cause of low sperm count often can't be found.

Medical causes

Low sperm count can be caused by health conditions such as:

• Varicocele. A varicocele (VAR-ih-koe-seel) is a swelling of the veins that drain the testicle. It's a common cause of male infertility. It can lower sperm count and quality. For some people, surgery to fix a varicocele can improve sperm count, movement and shape. It's not clear exactly why varicoceles cause infertility, but they might have an effect on the temperature in the testicles.
• Infection. Some infections can impact sperm health or the body's ability to make sperm. Certain repeated infections also can cause scarring that blocks the passage of sperm. Sexually transmitted infections such as gonorrhea or HIV can affect sperm count and fertility as well. So can infections from viruses, bacteria, or fungi that cause swelling of one or both testicles, or swelling of the coiled tube at the back of the testicle known as the epididymis. Most infections get better without causing any long-term issues. But some infections can cause lasting damage to the testicles. Still, healthcare professionals may be able to collect sperm as part of certain fertility treatments.

• Trouble with ejaculation. Ejaculation is the release of semen from the penis. It usually happens during orgasm. If semen enters the bladder during orgasm instead of leaving through the tip of the penis, that's called retrograde ejaculation. Various health conditions and certain types of surgery can cause retrograde ejaculation or complete lack of ejaculation. These include diabetes, spinal injuries, and surgery of the bladder, prostate or urethra.

  Certain medicines also can affect ejaculation. These include blood pressure medicines known as alpha blockers. Some ejaculation issues can be treated. Others are lifelong. Often, sperm can still be collected directly from the testicles as part of certain fertility treatments.

• Tumors. Cancers and tumors that aren't cancer both can affect the male reproductive organs directly. They also can affect these organs through the glands that release hormones related to reproduction, such as the pituitary gland. Surgery, radiation or chemotherapy to treat tumors in other areas of the body also can affect the body's ability to make sperm.
• Undescended testicles. During pregnancy, one or both of an unborn baby's testicles sometimes don't drop down into the scrotum. The scrotum is the sac that usually contains the testicles. Lower fertility is more likely in adults who were born with this condition.
• Hormone levels that become out of balance. A part of the brain called the hypothalamus and a gland at the base of the brain called the pituitary gland make hormones that are needed to create sperm. The testicles make hormones needed to make sperm as well. Changes in the levels of these hormones may mean that the body is having trouble making sperm. Changes in the levels of hormones that thyroid and adrenal glands make also may affect sperm count.
• Changes in the tubes that carry sperm. Various tubes in the body carry sperm. These tubes can be blocked due to various causes. Causes can include an injury from surgery, past infections and trauma. Conditions such as cystic fibrosis also can cause certain tubes not to develop or to form in irregular ways. A blockage can happen at any level, including within the testicle or in the tubes that drain the testicle.
• Genetic conditions. Some genetic changes passed from parent to child cause the male reproductive organs to develop in irregular ways. For instance, a condition called Klinefelter syndrome can cause the body to make less sperm. Other genetic conditions linked with infertility include cystic fibrosis, Kallmann syndrome and Kartagener's syndrome.

Some medical treatments also can cause a low sperm count, such as:

• Certain medicines. Medicines that can cause the body to make less sperm include some treatments for arthritis, depression, anxiety, low testosterone levels, digestive trouble, infections, high blood pressure and cancer.
• Prior surgeries. Certain surgeries may prevent you from having sperm in your semen. These surgeries include vasectomy, inguinal hernia repairs, surgeries of the scrotum or testicles, prostate surgeries, and large abdominal surgeries performed for testicular and rectal cancers. Often, surgery can be done to reverse the blockages that a past surgery caused. Or surgery can help retrieve sperm directly from the testicles and the coiled tube called the epididymis that's attached to each testicle.

Causes in a person's surroundings

Sperm count or function can be affected by being exposed to too much of the following:

• Industrial chemicals. Long-term exposure to insecticides, pesticides and organic solvents may play a part in low sperm counts.
• Heavy metals. Exposure to lead or other heavy metals can cause infertility.
• Radiation or X-rays. Exposure to radiation can cause the body to make less sperm. It can take years for the body to make typical amounts of sperm after this exposure. With high doses of radiation, the body might make less sperm than usual for life.
• Too much heat on the scrotum. Overheating the scrotum can affect sperm count and function.

Health, lifestyle and other causes

Other causes of low sperm count include:

• Drug use. Anabolic steroids taken to boost muscle strength and growth can cause the body to make less sperm. Use of cocaine or marijuana might lower the number and quality of sperm as well.
• Alcohol use. Heavy or ongoing alcohol use can lower testosterone levels and cause the body to make less sperm.
• Tobacco smoking. People who smoke might have a lower sperm count than people who don't smoke.
• Emotional stress. Long-term emotional stress, including stress over fertility issues, may affect semen quality.
• Weight. Obesity may directly impact sperm. Or it may cause hormone changes that lessen fertility.
• Sperm testing issues. A sperm count can appear lower than it really is due to various testing issues. For instance, a sperm sample may be taken too soon after your last ejaculation. Or the sample could be taken too soon after an illness or stressful event. Sperm count also can appear low if the sample doesn't contain all of the semen your penis released because some was spilled during collection. For this reason, results usually are based on a few samples taken over time.

Many risk factors are linked with low sperm count and other issues that can cause low sperm count.

Some risk factors are lifestyle choices, including:

• Smoking tobacco.
• Drinking alcohol.
• Using certain illicit drugs.

Some health conditions can be risk factors, such as:

• Being overweight.
• Being very stressed.
• Having certain past or present infections.
• Having had trauma to the testicles.
• Being born with a fertility disorder or having a blood relative with a fertility disorder.
• Having certain health conditions, including tumors and long-term illnesses.
• Having a history of undescended testicles.

Some treatments for health conditions also can be risk factors, including:

• Cancer treatments, such as radiation.
• Certain medicines.
• Vasectomy or major abdominal or pelvic surgery.

Some things in a person's environment also may raise the risk of a low sperm count. These include being exposed to toxins.

Infertility caused by low sperm count can be stressful for both you and your partner. Complications can include:

• Surgery or other treatments for an underlying cause of low sperm count.
• Expensive and involved fertility treatments such as in vitro fertilization (IVF).
• Stress from not being able to start a pregnancy.

To protect your fertility, try to stay away from known factors that can affect sperm count and quality. Take these steps:

• Don't smoke.
• Limit alcohol or don't drink it.
• Don't use illicit drugs.
• Talk with your healthcare professional to find out whether any medicines you take can affect sperm count.
• Stay at a healthy weight.
• Try not to become overheated.
• Manage stress.
• Do what you can to avoid exposure to pesticides, heavy metals and other toxins.

You may learn that you have a low sperm count if you get a healthcare checkup because you're having trouble getting your partner pregnant. At your appointment, your healthcare professional works to find out the cause of your fertility troubles. Even if your healthcare professional thinks you have a low sperm count, your partner's fertility also may need to be checked. This can help guide fertility treatment options for you and your partner.

General physical exam and health history

This includes an exam of your genitals. Your healthcare professional also asks questions about any inherited conditions, long-term health problems, illnesses, injuries or surgeries that could affect fertility. You also may be asked about your sexual habits and your sexual development.

Semen analysis

A sample of your semen is collected for testing as well. This is called a semen analysis. Your semen is checked under a microscope to see how many sperm are present. Sometimes, a computer helps measure sperm count.

Semen samples can be collected in a couple of ways. You can provide a sample by masturbating and ejaculating into a special container at the healthcare professional's office. Or you could use a special condom that collects your semen during sex.

New sperm are regularly made in the testicles. The sperm take about 42 to 76 days to mature. So a semen analysis reflects your environment over the past three months. The results of any lifestyle changes you've made won't show up for several months.

One of the most common causes of low sperm count is incomplete or improper collection of a semen sample. Sperm counts also often change on their own. Because of these factors, most healthcare professionals check two or more semen samples over time.

To help you collect an accurate sample, your healthcare professional likely will:

• Ask you to make sure that all of your semen goes into the collection cup or collection condom when you ejaculate.
• Ask you not to have sex or masturbate for 2 to 7 days before you collect a sample.
• Collect a second sample at least two weeks after the first.
• Tell you not to use lubricants while collecting your sample. These products can affect sperm movement.

Semen analysis results

If you have a low sperm count, your semen contains fewer than 15 million sperm in each milliliter or less than 39 million sperm total for the entire sample.

Your chance of getting your partner pregnant drops with lower sperm counts. Some people have no sperm in their semen at all. This is known as azoospermia.

Many factors are involved in pregnancy. The number of sperm in the semen is only one. Many people with low sperm counts are able to get their partners pregnant. Likewise, some people with typical sperm counts are not able to start pregnancies. Even if you have enough sperm, other factors are important to start a pregnancy. These factors include healthy sperm movement, also called motility.

Other tests

Depending on your semen analysis results, your healthcare professional might recommend more tests. Tests to look for the cause of your low sperm count and other possible causes of male infertility can include:

• Scrotal ultrasound. This test uses high-frequency sound waves to look at the testicles and supporting structures.
• Hormone testing. Your healthcare professional may recommend a blood test to check the levels of hormones made by the pituitary gland and testicles. These hormones play a key role in sexual development and in how much sperm the body makes.
• Post-ejaculation urinalysis. This urine test is done after you ejaculate. Sperm in your urine can mean that your sperm travel backward into the bladder instead of out of your penis during ejaculation. This is a condition called retrograde ejaculation.
• Genetic tests. When semen contains extremely low levels of sperm, certain genetic causes may be involved. A blood test can find out if you have symptoms of a genetic condition. Some people with genetic conditions decide not to get fertility treatment. That's because the gene changes that cause such conditions can be passed from parent to child.
• Testicle biopsy. This test involves removing small tissue samples from the testicles with a needle. It's not commonly used to find the cause of infertility.
• Transrectal ultrasound. A small, lubricated wand is placed into the rectum to check the prostate and look for blockages in the tubes that carry semen.

Treatments for low sperm count include:

• Surgery. For example, a varicocele can often be fixed with surgery. Or an obstructed vas deferens can be repaired. Past vasectomies can be reversed. If no sperm are present in the semen, sperm often can be collected directly from the testicles or epididymis.
• Treatments for infections. Antibiotics can cure an infection of the reproductive tract caused by germs. But this doesn't always restore fertility. And it's rare for genital tract infections to be linked with infertility.
• Treatments for sexual conditions. Medicine or counseling can help improve fertility in conditions such as erectile dysfunction or premature ejaculation.
• Hormone treatments and medications. These treatments can help if you have infertility caused by high or low levels of certain hormones. These treatments also may help if you have issues with the way your body uses hormones.
• Assisted reproductive technology (ART). Some couples have trouble becoming pregnant despite frequent sex. ART refers to treatments that can help couples become pregnant without sex. ART treatments involve collecting sperm through ejaculation or surgery or from donors. The way sperm is collected depends on your situation and wishes. Various types of ART are available. The sperm can be placed in the uterus through a tube, a process called intrauterine insemination. Or the sperm and eggs can be mixed together in a lab and placed in the uterus, a process called in vitro fertilization. Or a single healthy sperm can be injected into each mature egg before placement in the uterus. This is called intracytoplasmic sperm injection.

When treatment doesn't work

Rarely, male fertility problems can't be treated, and the affected person's sperm can't be used to start a pregnancy. If this happens to you, it's still possible to have a child. You and your partner can think about using sperm from a donor or adopting a child.

You can take steps at home to raise your chances of getting your partner pregnant, such as:

• Have sex more often. Have sex every day or every other day. Start 5 to 7 days before one of your partner's ovaries releases an egg, called ovulation. Keep having sex until two days after ovulation.
• Don't use certain lubricants during sex. Products such as Astroglide and K-Y Jelly, lotions, and saliva might affect sperm movement and function. Ask your healthcare professional about sperm-safe lubricants.
• Get regular exercise and eat a balanced diet.
• Aim to get at least seven hours of sleep a night.
• Take charge of stress.
• If you smoke tobacco or take illicit drugs, quit as soon as possible.
• Try not to become overheated.

If you have a low sperm count, you can take a multivitamin. But talk with your healthcare professional before you try any other supplement or type of alternative medicine. It's unclear whether supplements can help treat male infertility. And some supplements may affect medicines that you take or health conditions that you have.

For low sperm count, you can start by seeing your family healthcare professional. Then you might be referred to an infertility specialist.

Here's some information to help you get ready for your appointment, and what to expect.

What you can do

• Be aware of any restrictions before your appointment. When you make the appointment, ask if there's anything you need to do in advance. For instance, you may be told not to have sex or masturbate for a certain amount of time.
• Write down any symptoms you've had. Include any symptoms that might not seem related to the reason for which you made the appointment.
• Write down key personal information, including any major stresses or recent life changes.
• Find out whether you have a family history of fertility problems. Having a male blood relative, such as a brother or father, with fertility trouble or other reproductive conditions may give your healthcare professional clues to the cause of low sperm count.
• Find out from your parents if you had undescended testes or other conditions at birth or in early childhood.
• Make a list of all medicines, vitamins and supplements that you take. Include the amounts that you take.
• Take your partner along. Even if you have a low sperm count, your partner also may need tests. These tests can help find out whether your partner has a condition that could be preventing pregnancy. It's also good to have your partner with you to help keep track of any instructions your healthcare professional gives you. Your partner also can ask questions you may not think of.
• Write down questions to ask your healthcare professional.

Some basic questions to ask your healthcare professional include:

• What do you think may be causing my low sperm count?
• Other than the most likely cause, what are other possible reasons my partner and I haven't been able to become pregnant?
• What kinds of tests do I need?
• Will my partner also need tests?
• What treatments are available to raise my sperm count? Which do you recommend?
• Are there any restrictions that I need to follow?
• At what point should we think about trying options such as a sperm donor or adoption?
• Are there any brochures or other printed material that I can take home with me? What websites do you recommend visiting?

Feel free to ask any other questions that you think of during your appointment.

What to expect from your doctor

Some questions that your healthcare professional may ask you include:

• At what age did you start puberty?
• Have you had a vasectomy or a vasectomy reversal?
• Do you use drugs such as marijuana, cocaine or anabolic steroids?
• Have you been exposed to toxins such as chemicals, pesticides, radiation or lead, especially on a regular basis?
• Are you taking any medicines, including dietary supplements?
• Do you have a history of undescended testicles?