top of page

R is for Reasons: What factors can affect your sperm test results

Updated: Dec 6, 2023

This is Blog #4 in our S.P.E.R.M Blog series for National Fertility Awareness Week 2023

When we send your semen analysis report, it is important that we discuss the report with you. As healthcare professionals, we can recognise factors that may lead to suboptimal results. Where possible, we offer advice for lifestyle changes that could improve sperm health.

Here are our top 15 factors that can affect sperm quality:

#1 - Hot testicles

The testicles are on the outside of the body for a reason - to keep them cool. Sperm production takes place at a lower temperature that body temperature. If testes are hot, e.g. from sitting in a hot bath or sauna, or wearing tight underwear this can reduce sperm quality. A simple change to cooling the testicles can help fertility.

#2 - Injury

Trauma to the testicle can block the blood supply to the sperm producing tissue, and affect its ability to produce sperm.

#3 - Age

Sample volume and the quality of sperm tend to decrease with age. Semen from older men may have a lower volume, poor sperm performance, and increase in malformed sperm.

#4 - Illness

Any injury or operation (especially those involving the male sexual organs), or any infection (even a cold), or a high temperature can affect sperm function for up to 12 weeks.

#5 - Medication

Certain medications may suppress sperm production, lower sperm count and/or reduce their ability to achieve fertilisation.

#6 - STIs

Sexually transmitted infections can affect sperm production and motility, as well as cause inflammation of the tube at the back of the testicles which stores and transports sperm (epididymitis).

#7 - Exposure to toxins, chemicals or radiation

Chemical agents like lead, mercury, pesticides, etc. have been associated with decreased semen quality. Long exposure to radiation can decrease motility, and also sperm counts, viability and morphology.

#8 - Stress

A high level of stress hormones in the blood can lower sperm count, affect sperm production and also affect the sperm quality.

#9 - Genetic make-up & Karyotype

Many men have an extra X chromosome and are unaware. This condition, known as Klinefelter syndrome, can impact sperm production. We can provide a simple blood test to check if you are XY or XXY.

#10 - Weight

Being underweight or overweight has been linked to low levels of testosterone, loss of interest in sex and poor erections. Obesity can also overheat the testicles if there is an overhanging apron of fat.

"Your genetics load the gun. Your lifestyle pulls the trigger. – Mehmet Oz

#11 - Diet

A western diet tends to be high in carbohydrate and fat, and low in important elements, such as zinc and selenium. A healthy diet consisting of foods rich in nutrients like zinc and Vitamin B6, plus five portions of fruit and vegetables per day, may help improve sperm counts.

#12 - Recreational drugs

Drugs like marijuana and cocaine can cause lowered seminal fluid production, lowered blood supply to the penis, poor sperm quality and lowered sperm count.

Use of anabolic steroids and other hormones may shrink the testes, decrease the sperm count, and reduce sperm quality. Sperm production may

even stop altogether. Even protein supplements can impact on sperm production,

#14 - Alcohol

Alcohol can significantly reduce both the production and quality of sperm and the male hormone testosterone.

#15 - Smoking & vaping

Smoking and vaping can reduce the sperm count and motility, as well as significantly increasing the level of cadmium in the semen, and lowering zinc levels. Cadmium can damage sperm DNA.

Do you have any questions about any factors may have affected your sperm test results?

We hope this blog has helped you with some facts about these factors. For further information, to book a semen test or even if you want to discuss your semen analysis report, please contact us on:


70 views0 comments

Recent Posts

See All
bottom of page