Causes of low sperm count

What causes low sperm count

We use Advanced AI to translate our blog content. If the translation isn’t perfect, or if you have any queries about the content, our medical team is readily available to answer. Simply email [email protected]

Has your sperm test indicated you might have a low sperm count? This can be a tough and sometimes shocking thing to hear – but it doesn’t mean that fatherhood is off the cards. To understand the best way to deal with low sperm count, it’s firstly important to understand what could be causing it. There’s a whole range of factors that can lead to low sperm count – from genetics and medical conditions to poor diet and unhealthy lifestyle habits. Here we lay out some of the key causes of this specific male fertility issue – and give some advice on how to deal with them.

Lifestyle factors that could cause low sperm count

Lifestyle factors that could cause low sperm count

The good news is that in some cases, sperm count can be improved by adapting your lifestyle. If your low sperm count is influenced by lifestyle factors, you could see an improvement in a pretty short space of time – if these factors are addressed. Sperm regenerates every 72 days, so if your sperm count is looking a little low, it’s a good idea to adopt a healthy lifestyle that your swimmers will love (and make some changes if you aren’t) and then test 3 months later to see if things have improved. Here are some key lifestyle factors to consider:

Poor diet

There are certain foods that are the enemy of sperm health – and could be one of the causes of low sperm count. If your diet consists of lots of foods that are processed, high in sugar or full of trans fats, you should try to cut them out. Whilst snacks and treats are ok once in a while, try to reduce your intake and instead focus on eating some of these sperm superfoods. One of the most important diet habits is getting enough fruits and vegetables and you should be aiming for at least 5 servings a day.

Unhealthy weight

Research has indicated that overweight men are 11% more likely to have a low sperm count compared to men with a healthy BMI. Likewise, obese men were 42% more likely to have a low sperm count than their normal-weight peers and 81% more likely to produce no sperm – so keeping your weight in an optimal range is important if you are hoping to start a family. Maintaining a healthy diet is the most important thing in helping you reach your healthy weight goals and regular exercise can also play a part – as well as improving your cardiovascular health and circulation. 

Bad habits

We know that smoking, taking drugs and drinking alcohol excessively is not good for our overall wellbeing – and these things could also have an impact on your sperm health. If you are faced with low sperm count, try cutting back on these harmful habits and you may see an improvement over time!


Certain medications including testosterone replacement therapy, anabolic steroids and antidepressants could have an impact on your sperm health. You should never stop taking your medications without consulting your doctor,  but if you explain your sperm count is low and you’re concerned the medication could be impacting your fertility, they may be able to advise an alternative course of treatment whilst you’re trying to conceive

Hot Balls!

Sperm cells tend to die when they are exposed to too much heat – which can obviously play a part in lowering your sperm count. If you’ve been hitting the saunas and hot tubs, wearing tight underwear or doing lots of sport that crushes your balls for extended periods of time (aka cycling) this could be part of the reason your sperm count is low.


“Low sperm quality due to lifestyle factors is among the cases of “unexplained”. Several lifestyle factors such as smoking, obesity and low exercise level have been shown to have a negative impact on sperm count and motility.

Dr Fatin Willendrup, Head of Medical Affairs at ExSeed Health


Medical causes of low sperm count


Spermatocele – Everything You Need To Know

Most causes of low sperm count run a little deeper than your lifestyle choices. Certain medical conditions impact your sperm production or the journey of your sperm from testicles to your semen. Here are some you should be aware of.


One of the most common medical conditions to cause low sperm count is varicocele. This is basically when the veins surrounding the testicles and epididymis become enlarged, which makes it difficult for the testicles to regulate their heat – damaging your sperm cells. Around 1 in 6 men will have a varicocele at some point in their lives and whilst there are sometimes symptoms – like a swollen scrotum – many go undiagnosed until they start to impact fertility. However, if caught early, they can often be rectified with a simple surgery, and in many cases, sperm count can return to normal. We’ve written a handy guide to varicoceles here – but if you are concerned you may have one, definitely speak to your doctor ASAP.

Retrograde Ejaculation

Some conditions like diabetes and certain surgeries involving the urethra, bladder or prostate can lead to something called retrograde ejaculation. This basically means that when you orgasm, your semen goes into your bladder rather than out of your penis. This not only results in low sperm count but could also mean you have low sperm volume. If you’re concerned that retrograde ejaculation could be causing low sperm count – speak to your doctor. There are surgeries and assisted fertility treatments that can help you!

CBAVD (Congenital Bilateral Aplasia of Vas Deferens)

This fairly rare condition occurs when the tubes that carry sperm cells out of the testes (also known as the vas deferens) do not develop properly. In most cases the testicles develop and function normally – so sperm cells are present – but they do not become part of your semen, which can lead to a low sperm count result. Whilst this can be an intimidating diagnosis, in many cases, it is still possible to become a father thanks to assisted fertility treatments that can extract semen directly from the testicles for use in ICSI.

Genetic causes of low sperm count

Sometimes the reason behind your low sperm count is a little more complex than not getting enough vitamins in your diet. Some men who experience low sperm count and infertility are impacted by genetic defects that can cause sperm count and quality to be abnormal. Some of the most important ones to be aware of are:

Klinefelter Syndrome

Most men have XY chromosomes, but men with Klinefelter syndrome have an extra X chromosome – giving them XXY. This condition is more common than you may think with 1 in every 500-1000 guys having it. Men with Klinefelter syndrome often have very low testosterone levels, and might also find they have very low sperm count – which can impact their chances of conceiving naturally. There is no ‘cure’ for Klinefelter but some men can have sperm extracted directly from their testicles and used to fertilise eggs through assisted intracytoplasmic sperm injection (ICSI.)

Cystic Fibrosis Gene

Cystic fibrosis impacts over 70,000 people worldwide – with trouble breathing being the most well-known symptom. However, research has identified different forms of cystic fibrosis which can impact fertility in men. Men with this type of cystic fibrosis do not have a vas deferens, the tube that carries sperm from the testicles to the urethra – which would indicate a low or no sperm count on a test. In many cases, the sperm is being produced normally, but it is not coming out in the semen – so sperm cells could be extracted directly from the testicles and used in assisted fertility treatments (ICSI).

Y Chromosome Microdeletions

A less common genetic cause of low sperm count is Y Chromosome Microdeletions. Our genetic make-up is so complex and finely balanced, that if portions of the Y chromosome related to fertility are deleted –  it could have a knock-on effect on sperm count. The location of these deletions will determine whether a guy is totally infertile or if it’s possible to extract sperm from the testicle for use in assisted fertility.

Genetic counselling and donor sperm

Whilst with some genetic conditions there is the possibility of conception through assisted fertility treatments – there are other factors to consider. As genetic anomalies are hereditary, some men decide not to father children with their own sperm so as not to pass the condition or syndrome on. Whilst this can be a difficult decision to make, many would-be fathers want to protect their children from fertility or health issues down the line – and potentially life-threatening conditions such as cystic fibrosis. If you are diagnosed with a genetic condition like the ones mentioned above, you should be offered genetic counselling – and this is a safe space for you to discuss your options and various other routes to parenthood, including using donor sperm.

If you have received a low sperm count result through your ExSeed test, there is plenty of support available. You can follow our 90 Day Bootcamp to help you address key lifestyle factors, or chat to one of our medical experts who can give tailored advice on your next steps.

ExSeed home sperm test kit 2 test
ExSeed Home Sperm Test Kit (2 tests)


Refill Kit Monthly Subscription

£24.99 / month

ExSeed Combi


More to explore

Our products

ExSeed home sperm test kit 2 test
ExSeed Home Sperm Test Kit (2 tests)


ExSeed Refill Kit (5 tests)


ExSeed Combi


Wearing tight pants and underwear

Studies show that men who wear looser underwear have higher sperm concentration and total sperm count compared to men who wear tighter underwear. So, lose the tight clothes and wear something loose to give your testicles some air.

CONCLUSION: learn more about how heat can affect sperm quality here.


Besides higher mortality rate and various diseases, stress is associated with low sperm quality. Stress is known to be associated with lower testosterone levels and oxidative stress with both playing an essential role in producing and maintaining healthy sperm cells.

CONCLUSION: If you feel stressed, we recommend you get some help so you can have a balanced mental health. For a stress management guide, download the ExSeed app for free and start your personalized action plan today.

Physical activity

Scientific studies show that men who are physically active have better semen parameters than men who are inactive. Fertility specialists also state that regular physical activity has beneficial impact on sperm fertility parameters and such a lifestyle can enhance the fertility status of men.

Prioritizing exercise can help improve your overall health and result in healthy, fast swimming sperm cells that have good chances of fertilizing an egg.

CONCLUSION: Try incorporating exercise in your weekly schedule to you ensure exercising at least twice weekly. We recommend a combination of cardio training and strength exercise. Read more about exercise and male fertility on our blog.


Fast Food
Processed foods damage the health of sperm-producing cells and cause oxidative stress, which lead to poorer sperm quality. Heavy consumption of junk food (every week) can increase the likelihood of infertility since men who consume vast amounts of unhealthy food are at risk of having poor sperm quality. Besides harming your fertility, junk food enlarges your waistline, harms your cardiovascular system, kidneys, and more.

Eating more fruit and vegetables can increase your sperm concentration and motility. It’s important that you consume a healthy diet filled with antioxidants and that you eat vegetables every day. Foods such as apricots and red bell peppers are high in vitamin A, which improves male fertility by nurturing healthier sperm. Men who are deficient in this vitamin tend to have slow and sluggish sperm.

Sugary snacks/beverages: several times a week Excessive consumption of high sugar items can lead to oxidative stress, which negatively impacts testosterone levels and sperm motility. Sugary snacks and beverages are also highly associated with obesity and low fertility.
CONCLUSION: To boost sperm quality, stay away from fast food, processed food, and sugary snacks or beverages. You need to implement a healthy prudent diet filled with necessary superfoods needed for good sperm production. Check out our guide to Male Fertility Superfoods. For personalized guidance and support on how you can start improving your sperm health, check out the Bootcamp.


Direct heat can inhibit optimal sperm production and cause Sperm DNA damage. Sperm cells like environments that are a couple of degrees lower than body temperature. Avoid overheating from warm blankets, seat warmers, heat from your laptop, hot showers, and saunas.

Cigarette smoking

The exposure to tobacco smoke has significant negative effects on semen quality. The damage of cigarettes and nicotine of course depends on how many cigarettes you smoke per day and for how long, but even low usage (up to 10 cigarettes / day) can inhibit healthy sperm production.  

CONCLUSION: Stay as far away from cigarette smoking as possible if you care about your general health and your fertility. Read more here.

Cell phone

When you have your cell phone in your front pocket, your testicles are exposed to electromagnetic radiation, which studies have shown to damage the sperm cells. Put your phone in the back pocket of your pants or in your jacket pocket.


There is a clear association between obesity and reduced sperm quality. At least part of the reason for this is that obese men may have abnormal reproductive hormonal profiles, which can impair sperm production and lead to infertility. 

A BMI higher than 30 can lead to several processes in the body (overheating, increase in oxidative stress in the testes, sperm DNA damage, erectile dysfunction) that can have a negative impact on male fertility. This can result in problems when trying to conceive.  

CONCLUSION: BMI is one of the risk factors that influence semen quality and, for example, sperm motility.  


A beer or glass of wine now and then do not really harm sperm quality. But excess alcohol drinking (more than 20 units per week) can reduce the production of normally formed sperm needed for a successful pregnancy.

CONCLUSION: If you want to stay safe, stay under 14 units of alcohol per week. For more information on how alcohol can affect male fertility, take a look at our blog: “Alcohol and Sperm Quality”.


Studies show that women younger than 35 and men younger than 40 have a better chance of getting pregnant. Men can produce sperm cells almost through their entire life, but the sperm cell DNA is more fragile and prone to damage after the age of 40.

As men age, their testes tend to get smaller and softer resulting in a decline in sperm quality and production. These changes are partly because of an age-related decrease in testosterone level, which plays a very important role in sperm

production. Higher male age (>40 years) is not only associated with a decline in sperm production but also with increased sperm DNA fragmentation and worsened morphology (shape) and motility (movement). These negative effects make the sperm cells less qualified for egg fertilization.

CONCLUSION: with an age under 40, you shouldn’t have to worry much about age as a factor in itself. However, studies have shown a slow decline after the age of 30-35 years

and if you are above 40 years of age, your sperm quality can be affected due to increased sperm DNA damage resulting in a decrease of sperm motility and concentration. Remember that you cannot evaluate the quality of a sperm sample by just looking at it – this requires a sperm analysis.