What is oligospermia (low sperm count)?

What is oligospermia
What is oligospermia ?

What is oligospermia (low sperm count)?

Oligospermia is a term that means you have a low sperm count. One medical definition is that you have fewer than 15 million sperm in 1 milliliter of semen. A typical sperm count is more than 15 million sperm per 1 milliliter of semen.

Besides being known as low sperm count, oligospermia is also called oligozoospermia. A severely low sperm count (fewer than 5 million sperm in 1 milliliter of semen) is also known as severe oligospermia.

What is the difference between oligospermia and azoospermia?

Oligospermia means that you do have a measurable amount of sperm in your semen, but the numbers are lower than the typical numbers. If you have azoospermia, it means there no sperm seen in your semen.

Having a low sperm count is a significant factor in infertility. You may be infertile if you’ve been trying to get pregnant (or get someone pregnant) for a year and haven’t yet done so. This means that for at least a year you’ve been having regular sex without using birth control methods.

How common is oligospermia?

Researchers aren’t sure how many people have oligospermia. The condition isn’t usually diagnosed unless a couple is trying to conceive and can’t. There are an estimated 180 million couples throughout the world who are dealing with infertility.

Infertility among people who have been assigned male at birth contributes to about half of the infertility issues overall. (Healthcare providers may call this male infertility or male-factor infertility.) This figure of about 50% includes situations where male factor infertility is the only factor and those more common situations where there are fertility factors in both partners.

What are the signs and symptoms of oligospermia?

The main sign or symptom of a low sperm count is the inability to conceive a baby with a partner after one year of unprotected sexual intercourse.

Low Sperm Count
Low Sperm Count

What causes a low sperm count?

There are a variety of things that could cause you to experience oligospermia or other sperm disorders. The list of causes include:

  • Diseases, including those related to genetics, infection, hormones and obstructions (blockages).
  • Environmental toxins.
  • Heat.
  • Drugs.

Diseases and conditions

Some of the diseases that can cause a low sperm count include:

  • Genetic conditions such as Klinefelter syndrome and cystic fibrosis.
  • Infections such as sexually transmitted diseases, urinary tract infections, and viral illnesses including mumps.
  • Issues like low testosterone and other hormonal abnormalities. Hypogonadism is a condition where the sex glands don’t produce enough sex hormones.
  • Blockages that stop sperm from leaving your body.


Toxins aren’t good for any part of your body, including sperm count. Some of the toxins that are present in the environment include heavy metals like arsenic, cadmium, lead and mercury.


Your testicles work best at a particular temperature, which is slightly lower than your body temperature. Heat-related situations that affect sperm production include:

  • Having undescended testicles. If the testicles are still up near the groin, they’re too hot.
  • Having varicocele. These twisted veins can be large and can increase the temperature of the testicles.
  • Spending a long time in hot tubs. This cause may be reversed – your sperm count could increase once you stop spending time in hot water.

Medications and drugs for oligospermia

Both prescribed medications and non-prescription substances can make your sperm count low. There are many categories of medications that can be involved. Some of these medications include:

  • Testosterone.
  • Methadone.
  • Nitrofurantoin.
  • Lamotrigine.
  • Clomipramine.
  • Paroxetine.
  • Prednisone.
  • Methotrexate.
  • Finasteride.
  • Sirolimus

How is oligospermia diagnosed?

Your healthcare provider will take a medical history and do a physical examination. They may order other tests, including:

  • Semen analysis and sperm function tests.
  • Urinalysis to test for retrograde ejaculation (sperm moving backward inside you).
  • Imaging tests of your reproductive organs, including transrectal and scrotal ultrasounds.
  • Tests of your endocrine system to measure hormone levels.
  • Testing for genetic disorders.

How is oligospermia treated?

Your provider’s treatment suggestions will depend on the cause of the oligospermia. You may increase your sperm count by stopping medications or behaviors that are contributing to low sperm levels.

Other causes may need other treatments. For instance:

  • You may need surgery to treat a varicocele or blocked sperm ducts.
  • Your provider may prescribe hormone supplements.
  • Your provider may prescribe antibiotics for infections.
  • Your provider may suggest counseling to deal with issues like erectile dysfunction or premature ejaculation.

Difference Between Normal Sperm Count and Low Sperm Count

What is Low Sperm Count?
Low Sperm Count Symptoms
Low Sperm Count Diagnosis
Types of Low Sperm Count or Oligospermia
Low Sperm Count Causes
Tips to Increase Sperm Count Naturally
Low Sperm Count Treatment
Low Sperm Count Success Story
Low Sperm Count Treatment
Can a Man with Low Sperm Count have a Baby?
What is the Main Cause of Low Sperm Count?
Can a Low Sperm Count be Treated?
Can Low Sperm Count lead to Miscarriage?
How can you tell if a Man is Infertile?
What does Low Sperm Count Look Like?
What Cause Low Sperm Count?

What is low sperm count?

Low sperm count or Oligospermia means that the number of sperm in a man’s ejaculate or semen is below normal. A total lack of sperm in the ejaculate is known as Azoospermia. Often semen with a decreased sperm concentration may also show significant abnormalities in sperm morphology and motility.

A sperm count in the ejaculate can vary throughout a man’s life. A healthy sperm count is necessary for fertility. The World Health Organisation (W.H.O) in its latest statement of semen quality (2010), considers a sperm count at 15 million/mL or above as normal sperm count. And anything below that is considered as sperm count low and diagnosed as oligospermia or oligozoospermia.

Low Sperm Count Symptoms

The primary symptom is the inability to have a baby. There can be no other noticeable signs and symptoms. In some cases, a fundamental issue, for example, a hereditary chromosomal abnormality, a hormonal imbalance, dilated testicular veins or a disorder that obstructs the passing of sperm could potentially cause warning signs. The low sperm count signs or oligospermia symptoms include:

  • Problems with sexual function, for example, low sex drive or difficulty maintaining an erection (erectile dysfunction).
  • Pain swelling or a lump in the testicle area.
  • Decreased facial or body hair or other signs of a chromosomal or hormonal imbalance is also one of the low sperm count symptoms.

Low Sperm Count Diagnosis

Most of the cases of oligospermia are detected once the man tries to become a father, and when pregnancy is not achieved in a natural way, even after a year of regular unprotected intercourse, then both the male and female partner must undergo tests to check their fertility conditions.

A gynaecologist or an infertility consultant may order a semen analysis test. The diagnosis of low sperm count or oligospermia is based on low sperm count found in a semen analysis test. However, two tests should be performed to confirm the results. A semen analysis test usually checks at along with pH, etc.:

Semen Analysis Test and low sperm count – oligospermia

Main Parameters that are Seen in a Semen Analysis Test

Ejaculate Volume( > 1.5 mL)
Sperm Concentration( > 15 million/mL)
Total Motility( > 40%)
Progressive Motility(>= 32%)
Semen Analysis Test

It is more than just a sperm count that matters for a pregnancy to occur, in normal methods of conception as well as assisted methods such as artificial/intrauterine insemination or In vitro fertilisation.

Low sperm count in the ejaculate may at times be accompanied by an abnormality in sperm motility and morphology, and if the motility is poor, the sperm will not be able to reach the oocyte. If the morphology is poor, the sperm would not be able to penetrate the egg. Hence fertilisation is affected.

Types of Low Sperm Count or Oligospermia

When a man has less than 15 million sperm per mL, depending on how low his count is, we distinguish between different levels of severity. The levels are used to diagnose how severe the problem is on a case to case basis, and the treatment would be totally dependent on the level of oligospermia. It is classified in the following groups.

Types of Low Sperm Count
TypesSperm concentration in Ejaculate
Normozoospermia>15 million sperm/mL
Mild Oligospermia10 million to 20 million sperm/mL
Moderate Oligospermia5 million to 10 sperm/mL
Severe Oligospermia1 to 5 million sperm/mL
Cryptozoospermia0 to rare sperm, hidden sperms found after centrifugation
Azoospermia0 sperm
Types of Low Sperm Count

Types of Oligospermia


When the number of sperm found in the semen ranges from 10 million to 20 million sperm per millilitre.


When the number of sperm found in the semen ranges from 5 million to 10 million sperm per millilitre. Improvement can be achieved in these cases following proper treatment and a healthy lifestyle for a few months. Semen analysis should be repeated after a few months.


When the number of sperm found in the semen ranges from 1 to 5 million sperm per millilitre. Pregnancy, in this case, can only be achieved by ART (Assisted reproductive technology).


When the number of sperm found in the semen sample after centrifugation is 0 to rare. Pregnancy, in this case, also can only be achieved by ART (Assisted reproductive technology).


When there is no sperm found in the ejaculate, the condition is called azoospermia. Pregnancy, in this case, can only be achieved by ART (Assisted reproductive technology).

Even though pregnancy with oligospermia is possible, still it should be kept in mind that depending on the severity of the case, infertility treatments are available, which allow couples to overcome these obstacles and allow fertilisation to occur successfully.

Low Sperm Count Causes

Most men are completely unaware of their fertility status unless they can make a female pregnant till then they are in the dark. Many reproductive and non-reproductive causes have been reported, but in most cases, the cause remains unexplained because a low sperm count can occur as a temporary alteration. Low sperm count can be caused by a number of medical issues, environmental factors and lifestyle choices. Treatment will be totally dependent on the cause of the problem.

Medical Causes – A low sperm count can be caused by a number of health issues and medical treatment.

  • Varicocele – It results in reduced quality of sperm. Enlarged veins in a man’s scrotum disrupt blood flow to the testicle, this causes the temperature in the testicles to increase, and an increase in the temperature can impact sperm production.
  • Infections – This interferes with sperm production or sperm health and can cause permanent testicular damage as well. Infections like epididymitis (inflammation of the epididymis), orchitis (inflammation of the testicles) can reduce sperm count in semen. Even sexually transmitted disease can cause low sperm count.
  • Ejaculation – Such problems due to some health issues like diabetes, spinal injuries, surgery of the bladder, prostate or urethra can cause retrograde ejaculation that is semen enters the bladder instead of flowing out from the tip of the penis.
  • Tumours – Surgery, radiation or chemotherapy to treat tumours can lower sperm count.
  • Hormonal Imbalance – the brain and the testicles produce several hormones that are responsible for ejaculation and sperm production, and a hormonal imbalance may lower sperm count.
  • Medications – Some medicines like beta-blockers, antibiotics and blood pressure medications can cause ejaculation problems and reduce sperm count.
  • Genetic Defects – Men with a severely low sperm count that is when the count is less than 5 million sperm per millilitre of semen have a higher risk of genetic abnormalities. These may result in structural or functional testicular abnormalities. Only 20-30% of men with severe oligospermia and azoospermia are finally diagnosed to have a specific disorder. Identified genetic causes of low sperm count can be Klinefelter’s syndrome, Y chromosome deletion, cystic fibrosis.

Environmental Causes – Exposure to environmental toxins and chemicals can affect sperm production and function.

  • Industrial Chemicals – Extended exposure to benzene, toluene, xylene, herbicides, pesticides, organic solvents, painting materials might lead to low sperm count.
  • Heavy Metal Exposure – Exposure to lead or other heavy metals can cause low sperm count.
  • Radiation or X-rays – Exposure to radiation can reduce sperm production and function. With high doses of radiation, sperm production can be permanently reduced.
  • Overheating of Testicles – An increase in the temperature reduces sperm production and function. Use of hot water tubs, saunas, sitting for long hours, wearing tight clothing increases the temperature in the scrotum, which results in reduced sperm production.

Lifestyle Choices – Other causes of low sperm count, includes one’s lifestyle choices.

  • Drug Use – Anabolic steroids that are taken to stimulate muscle strength and growth can cause the testicles to shrink and hence, sperm production decreases. Use of illegal drugs too reduce the number and quality of sperm.
  • Smoking and Alcohol Consumption – Men who smoke more than 20 cigarettes in a day tend to have a low sperm count. And excess consumption of alcohol can lower testosterone levels and hence cause decreased sperm production.
  • Stress – Severe or prolonged psychological stress might cause hormonal imbalance, which might cause a low sperm count.
  • Weight – Obese people can have a low sperm count. Adipose tissues (fat) converts testosterone to oestrogen, and extra oestrogen in a man’s body can negatively impact sperm count and sperm quality. Excessive body fat and low muscle mass keep testosterone levels below normal leading to poor quality of sperm.

Depending on the origin where the alteration in sperm production has occurred, the causes can be categorised under three types.

Causes according to the origin of alteration – sperm production

PRE-TESTICULAR OLIGOZOOSPERMIC CAUSES(Refers to hormonal imbalance that interferes with sperm production and external factors that have an impact on the body)TESTICULAR OLIGOZOOSPERMIC CAUSES(Caused by testicular diseases)POST-TESTICULAR OLIGOZOOSPERMIC CAUSES(Refers to ejaculation problems, sperm production function works properly, but problem appears during the time of ejaculation)
Medical treatment which affects sperm productionVaricoceleObstruction of the vas-deferens
Cannabis and alcoholAgeInfection such as prostatitis
Junk foodInjury to the testicleRetrograde ejaculation
HypogonadismGenetic abnormalitiesErectile dysfunction
Causes according to the origin of alteration – sperm production

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