Are there any symptoms?

• cystitis
  
  
• change in vaginal discharge
  
  
• mild lower abdominal pain.
  
  

These are very 'non-specific’ symptoms and can be caused by other infections and diseases. If you go to a GP or family planning doctor with these symptoms, make sure you have a chlamydia test. You are entitled to ask for the test if you aren't offered it.

In men, chlamydia is the most common cause of discharge from the penis. Sometimes chlamydia can cause mild irritation at the tip of the penis (urethra) that disappears after two or three days.

Many men will wait to see if the discomfort goes away. While the discomfort may disappear, the man can still harbour the infection.

If in doubt, get tested. Otherwise, you could put yourself at risk of inflamed and swollen testicles, and pass chlamydia on to your partner.

What complications can chlamydia cause?

• In some women chlamydia can cause pelvic inflammatory disease (PID), also know as pelvic infection. It can damage the Fallopian tubes that carry eggs from the ovaries to the womb. The tubes may stop working properly and can become completely blocked.
  
  
• Chlamydia is the most common preventable cause of infertility in women. When the Fallopian tubes are blocked, no pregnancy is possible naturally. One option is IVF (in-vitro fertilisation), but availability on the NHS is patchy and has variable success rates.
  
  
• Women with damaged tubes do occasionally fall pregnant, but there is an increased risk of the pregnancy developing in the tubes rather than the womb. This is called an ectopic pregnancy. The tube can split apart causing serious pain and bleeding. This is an emergency, because the bleeding can be life threatening.
  
  
• Infection sometimes leads to pain in the lower abdomen that is often mistaken for some other problem rather than pelvic infection.
  
  
• Chlamydia infection can affect sperm function and male fertility. It is the most common cause of inflammation in the testicles and sperm-conducting tubes (epididymo-orchitis) in men under the age of 35. This causes pain, swelling and redness on the affected side of the scrotum, or on both sides.
  
  
• Chlamydia can also trigger joint inflammation in some men. Although this is uncommon, it can be difficult to treat.