Low Sperm Count Causes Diagnosis and Treatment Options for Male Infertility
A sperm count result can feel like a verdict, but it is usually the start of an investigation, not the end of the story. Sperm production changes over time, and one test result rarely explains everything on its own.
Low sperm count, also called oligospermia, means there are fewer sperm in the semen than expected for natural conception. It does not mean pregnancy is impossible. It does mean the chances may be lower, because fewer sperm are available to travel through the female reproductive tract and fertilise an egg.
This guide explains what the result means, how it is assessed, why repeat testing may be needed, and how doctors look for causes and treatment options. It is for general information only and does not replace medical advice from a fertility specialist or doctor.
What oligospermia means and how sperm count affects conception
Oligospermia describes a sperm concentration or total sperm number below the reference range used by the laboratory. The result may be mild, moderate, or severe, depending on how far below the expected range it falls.
Sperm count is only one part of male fertility. A sample can have a lower count but good movement, or a normal count with poor motility. Conception depends on several factors working together, including:
The number of sperm in the ejaculate
How well sperm move
The shape and structure of sperm
Semen volume
Timing of intercourse or insemination
Ovulation and fallopian tube health
Age and fertility factors in the partner
That is why a result should be read as part of a full fertility picture. A lower count may reduce the odds each cycle, but it does not always rule out natural conception.
Some people first hear about the issue after a routine fertility check. Others have testing after trying to conceive for a year, or sooner if there are known risk factors such as previous testicular surgery, cancer treatment, or a history of undescended testes.
How doctors assess sperm count
A semen analysis is the main test used to assess sperm count and other semen parameters. The sample is usually produced by masturbation into a sterile container, after a recommended period of abstinence. The timing matters because very short or very long abstinence can affect the result.
The laboratory may assess:
Test measure | What it shows |
Semen volume | The amount of fluid produced |
Sperm concentration | The number of sperm in each millilitre |
Total sperm count | The estimated number of sperm in the full sample |
Motility | How many sperm move and how well they move |
Morphology | The proportion of sperm with typical shape |
pH and appearance | Clues about infection or blockage |
White blood cells | Possible inflammation or infection |
A sperm count test also depends on sample quality. If some of the sample is missed, if it arrives late, or if it is exposed to heat or cold, the result may not reflect the usual situation.
Why one abnormal result may not tell the whole story
Sperm production takes roughly three months from start to finish. Illness, fever, medication changes, stress, heat exposure, alcohol intake, and other factors can all affect the result for a period of time.
This is why doctors often repeat testing, especially when the first result is unexpected or abnormal. A repeat sample may show improvement, confirm the pattern, or reveal variation between tests.
A single abnormal result may be followed up if:
The count is very low
There are no sperm seen in the sample
Motility or morphology is also reduced
The sample collection was difficult or incomplete
There has been a recent fever or illness
The couple has been trying to conceive for some time
Repeat testing helps avoid over-interpreting a temporary dip. It also gives a more reliable baseline before treatment decisions are made.
Common causes of a reduced sperm count
Many different conditions can reduce sperm production or affect sperm transport. Sometimes more than one factor is involved. In some cases, no clear cause is found.
Varicocele
A varicocele is an enlargement of veins around the testicle, often described as feeling like a “bag of worms” on examination. It can raise the temperature around the testicle and may affect sperm production.
Not every varicocele causes fertility problems, and not every varicocele needs treatment. Doctors look at testicular size, symptoms, semen results, and the couple’s wider fertility picture before deciding what to do.
Hormonal problems
Sperm production relies on signals between the brain and testicles. The pituitary gland releases hormones that tell the testicles to make sperm and testosterone.
Hormonal causes may include:
Low testosterone
Problems with follicle-stimulating hormone or luteinising hormone
Raised prolactin
Thyroid problems
Use of anabolic steroids or testosterone treatment
Testosterone treatment can be a particular issue. Although it may improve energy or libido in some settings, external testosterone can switch off the body’s own sperm production. This effect may be reversible, but recovery can take time and needs specialist guidance.
Infections and inflammation
Some infections can affect sperm production, block sperm transport, or cause inflammation in the reproductive tract. Possible causes include sexually transmitted infections, urinary tract infections, prostatitis, or previous infections affecting the testicles.
Symptoms may include discomfort, discharge, pain when passing urine, pelvic pain, or blood in semen. Some infections cause few symptoms, so testing may still be needed when the history suggests risk.
Genetic conditions
Genetic factors can affect sperm production, especially when the count is very low or no sperm are seen. Examples include chromosome differences and small missing sections on the Y chromosome.
Genetic testing is not needed for everyone. It is usually considered when the sperm count is extremely low, there are signs of impaired testicular function, or assisted reproductive treatment is being planned.
Medications and medical treatments
Several medicines and treatments can affect sperm count. These may include:
Anabolic steroids
Testosterone therapy
Some chemotherapy drugs
Some medicines used for autoimmune disease
Certain long-term pain medicines
Some treatments for hair loss or prostate symptoms
Some antidepressants or psychiatric medicines, mainly through sexual side effects
No one should stop prescribed medicine without medical advice. A doctor can review whether a treatment may be affecting fertility and whether a safer alternative is suitable.
Heat exposure
The testicles sit outside the body because sperm production works best at a slightly cooler temperature. Repeated heat exposure may affect results in some people.
Common sources include:
Frequent hot baths or saunas
Tight clothing that traps heat
Using laptops directly on the lap
Occupations with high heat exposure
Recent fever
The effect is often linked to duration and frequency. If heat is a factor, improvement may take several months after reducing exposure.
Lifestyle factors
Lifestyle does not explain every case, but it can contribute. Smoking, heavy alcohol intake, recreational drug use, poor sleep, obesity, and severe stress are all linked with poorer semen parameters in some studies.
Diet and exercise matter too, not because there is a perfect “fertility diet”, but because general metabolic health supports hormone balance and sperm production.
Useful changes may include:
Stopping smoking
Reducing alcohol intake
Avoiding recreational drugs
Building regular moderate exercise
Working towards a healthy weight
Sleeping consistently
Avoiding anabolic steroid use
Previous surgery or injury
Surgery can affect fertility if it involves the testicles, groin, pelvis, bladder, prostate, or reproductive ducts. Relevant history may include:
Undescended testicle surgery
Hernia repair
Vasectomy
Testicular torsion
Testicular trauma
Pelvic or prostate surgery
Cancer treatment
Previous surgery can reduce production, block sperm transport, or affect ejaculation. The likely mechanism depends on the operation and clinical history.
How doctors investigate the underlying cause
A good assessment looks beyond the number on the report. The aim is to understand whether the problem is related to sperm production, sperm transport, hormones, infection, ejaculation, or a temporary factor.
Medical history
The doctor may ask about:
How long conception has been attempted
Previous pregnancies with the same or different partner
Timing of intercourse
Puberty and sexual development
Erectile or ejaculation problems
Past infections
Testicular pain, swelling, or injury
Previous surgery
Medication and supplement use
Steroid or testosterone use
Smoking, alcohol, and recreational drugs
Heat exposure
Family history of fertility or genetic conditions
These questions can feel personal, but they often provide the clearest clues.
Physical examination
An examination may include checking testicular size and consistency, looking for a varicocele, assessing the vas deferens where possible, and checking for signs of hormonal imbalance.
Testicular size can be relevant because smaller testes may suggest reduced sperm production. A missing vas deferens, where sperm normally travel, may point towards a blockage or congenital condition.
Blood tests and other investigations
Hormone testing may include testosterone, follicle-stimulating hormone, luteinising hormone, prolactin, and sometimes thyroid tests or other markers. The pattern can help distinguish between testicular causes and hormone signalling problems.
Other tests may be used when appropriate, such as:
Urine or swab testing for infection
Scrotal ultrasound for varicocele or testicular concerns
Genetic testing for very low counts
Post-ejaculation urine testing if retrograde ejaculation is suspected
Specialist imaging if a blockage is possible
The right tests depend on the history, examination, and semen results. Not every person needs every investigation.
Treatment options depend on the cause
Treatment works best when it targets the underlying issue. In some cases, the goal is to improve the chance of natural conception. In others, treatment prepares for assisted reproduction.
Treating infections or inflammation
If an infection is found, antibiotics or other treatment may be prescribed. Partners may also need testing or treatment, depending on the infection. Semen results may take time to improve after inflammation settles.
Correcting hormonal problems
Some hormonal problems can be treated with medicines that encourage the body to produce its own testosterone and sperm. This is specialist care, especially if previous testosterone or anabolic steroid use is involved.
If raised prolactin, thyroid disease, or pituitary problems are found, treating those conditions can sometimes improve fertility.
Managing varicocele
Varicocele repair may be considered when there is a clear varicocele, abnormal semen results, and infertility. Treatment can involve surgery or embolisation. The benefit varies, so selection matters.
Improvement, when it occurs, is not immediate. Since sperm production takes months, follow-up testing is usually needed later.
Addressing lifestyle and heat factors
Lifestyle changes can support fertility, especially when there are clear risk factors. These changes are not a guaranteed cure, but they may improve overall reproductive health and make treatment more effective.
A practical plan might include stopping smoking, reducing alcohol, avoiding hot baths and saunas for a period, improving sleep, and reviewing gym supplements for hidden hormones or anabolic agents.
Surgery for blockage or sperm retrieval
If sperm production is present but sperm cannot reach the ejaculate, surgical options may be possible. This may include reversal after vasectomy in selected cases or procedures to retrieve sperm directly from the epididymis or testicle.
Retrieved sperm may be used with assisted reproductive treatment, depending on the circumstances.
Assisted reproductive techniques
When the count remains low, assisted reproduction can help sperm reach the egg.
Options may include:
Intrauterine insemination, often called IUI, in selected mild cases
In vitro fertilisation, known as IVF
Intracytoplasmic sperm injection, known as ICSI, where a single sperm is injected into an egg
ICSI is often used when sperm numbers are very low, motility is poor, or sperm have been surgically retrieved. The best option depends on sperm results, the age and fertility health of the partner, previous treatments, and personal preferences.
When to seek specialist help
Specialist assessment is sensible if a semen result is abnormal, if conception has not happened after regular unprotected sex for 12 months, or sooner if the female partner is over 35 or there are known fertility concerns.
It is also worth seeking advice promptly if there is a history of:
Undescended testes
Testicular cancer or chemotherapy
Vasectomy or pelvic surgery
Anabolic steroid or testosterone use
Very small testes
No sperm seen on a test
Painful swelling or a suspected varicocele
For a focused male fertility assessment in London or online, you can book an appointment with The Male Factor Fertility.
FAQs
Can low sperm count improve naturally?
Yes, sometimes. Counts can improve after illness resolves, heat exposure stops, lifestyle factors change, or medication issues are addressed. Since sperm production takes around three months, improvement is usually assessed over months rather than days.
Does oligospermia mean natural pregnancy cannot happen?
No. Oligospermia can reduce the chance of conception, but pregnancy may still happen, especially if motility is good and there are no major fertility issues in the partner. The likelihood depends on the severity and the wider fertility picture.
How many semen tests are usually needed?
Many doctors repeat testing if the first result is abnormal or unexpected. Results can vary, and a second test helps confirm whether there is a persistent pattern.
Can testosterone treatment cause male infertility?
Yes. External testosterone can suppress the hormonal signals needed for sperm production. Anyone using testosterone and trying to conceive should speak to a fertility specialist before making changes.
What happens if no cause is found?
Sometimes the cause remains unexplained. Treatment may still be possible, including lifestyle review, monitoring, fertility medication in selected cases, or assisted reproductive techniques such as IVF or ICSI.
The key takeaway
A reduced sperm count is a signal to investigate, not a final answer. The most useful next step is to confirm the result, look for treatable causes, and match treatment to the underlying problem. With the right assessment, many people have options, from medical treatment and surgery to assisted reproduction.
Comments