Understanding male infertility: causes and symptoms

Approximately one in seven men in the UK experience fertility issues, making male infertility more common than people may realise. Despite its prevalence, the condition often goes unnoticed, which is why recognising the symptoms is important for identifying and addressing the problems early on.

Causes of male infertility

Several factors can contribute to male infertility and being aware of the causes may help prevent issues from developing.

Sperm quantity and quality – A low sperm count or no sperm at all can significantly impact your chances of conception. If the amount of sperm can move properly, it may struggle to reach and fertilise the egg. In some cases, the number of sperm with a normal head, body and tail is too low and this can make natural pregnancy less likely too.

Smoking – Smoking can reduce sperm count and sperm quality. It is also thought that smoking can cause the DNA in sperm cells to break down, which can potentially lead to infertility.  

Diabetes – Research has linked male infertility to diabetes, which can affect sperm quality and quantity. Diabetes can cause erectile dysfunction and ejaculation issues.

Damaged testicles – Infections, testicular injuries and surgery, testicular cancer can cause damaged testicles and severely impact semen quality.

Ejaculation disorder - Ejaculation problems can be another cause of infertility. This is a condition that can make it difficult for individuals to release semen and sperm during sexual intercourse.

Sexually transmitted infections (STIs) - Infections including chlamydia, gonorrhoea and syphilis can lead to infertility in men if they are untreated. STIs can damage the reproductive system, causing inflammation, scarring, blockages, and reduced sperm production or motility. 

X-rays - Radiation exposure, such as X-rays, can affect and reduce sperm production, though it usually returns to normal over time.

Diet - Maintaining a healthy diet rich in fruits and vegetables is essential. Avoiding foods high in fat and sugar is important, as these can negatively impact sperm quality. Additionally, excessive alcohol consumption can alter hormone levels, leading to decreased sperm production and quality. While moderate caffeine intake is generally safe, excessive amounts may damage sperm. It's also advisable to avoid fish with high mercury levels, such as tuna and swordfish, as they can significantly affect reproductive health

Reviewed by Justin Chu, Medical Director at TFP Oxford Fertility.