What male fertility depends on

Male fertility is influenced by several factors, including:

  • Sperm production and quality
  • Hormonal balance
  • Testicular health
  • General physical and mental health
  • Lifestyle factors

Problems may affect sperm count, movement or shape, or interfere with sperm delivery.

Common causes of male fertility problems

These include:

  • Low sperm count
  • Reduced sperm movement
  • Abnormal sperm shape

Many men with abnormal semen results have no obvious symptoms.

Hormones involved in sperm production include:

  • Testosterone
  • Follicle-stimulating hormone (FSH)
  • Luteinising hormone (LH)

Hormonal causes are less common but important to identify.

Fertility may be affected by:

  • Smoking
  • Excess alcohol
  • Obesity
  • Recreational drug use
  • Heat exposure to the testes
  • Stress and poor sleep

Addressing these can improve fertility over time.

Less common causes include:

  • Varicocele
  • Previous testicular injury or infection
  • Surgery affecting the reproductive tract
  • Certain genetic conditions

How GPs assess male fertility

Initial GP assessment usually includes:

  • How long pregnancy has been attempted
  • Frequency and timing of intercourse
  • Medical and medication history
  • Lifestyle factors
  • Sexual function and erectile concerns

Fertility is always considered as a couple issue, even when symptoms appear to be on one side.

Semen analysis explained

Semen analysis is the key initial test for male fertility.

It assesses:

  • Sperm count
  • Sperm movement
  • Sperm morphology

Results can vary, so an abnormal result is often repeated before conclusions are drawn.

A single abnormal test does not always mean permanent infertility.rather than routine and should be discussed with a GP for a full assessment.

Hormone tests and blood tests

Blood tests may be considered if semen results are abnormal or if symptoms suggest hormonal involvement.

Tests may include:

  • Testosterone
  • FSH and LH
  • Prolactin
  • Thyroid function tests

Hormone testing is targeted, not routine.


What male fertility tests can and cannot tell you

  • Identifying sperm production problems
  • Detecting hormonal causes
  • Guiding referral decisions
  • Predict natural conception with certainty
  • Replace assessment of the female partner
  • Guarantee success of fertility treatment

Normal tests do not always mean pregnancy will happen quickly, and abnormal tests do not always prevent conception.

Testosterone and fertility

Testosterone is important for male health, but external testosterone treatment can suppress sperm production.

Men trying to conceive should not start testosterone therapy without specialist advice.

When referral to specialist care is appropriate

Referral may be considered if:

  • Semen analysis is persistently abnormal
  • There is suspected hormonal or structural disease
  • Pregnancy has not occurred after appropriate time
  • There are significant risk factors or previous testicular problems

GPs aim to ensure timely and appropriate referral.

Emotional impact of fertility concerns

Fertility difficulties can affect confidence, relationships and mental wellbeing. Men may be less likely to talk about fertility concerns, but support and clear information can make a significant difference.

GPs can help address both physical and emotional aspects of fertility concerns.


Further Reading and Hub Links

Visit our Men’s Health hub or browse more health topics in the AccessGP Knowledge Base.

If you have concerns about male fertility, a GP can assess possible causes, arrange appropriate tests, and advise on next steps or referral.

Last reviewed by Dr Zamiel Hussain, GMC registered GP
Updated: 14 January 2026