Symptoms of threadworms 

Threadworms often go unnoticed by people who have them, but symptoms can include:

  • intense itching around the anus (or the vagina in girls), particularly at night when the female worms are laying eggs
  • disturbed sleep as a result of the itching, which can lead to irritability

In some cases, you may spot threadworms on your bed clothes or sheets at night, or you may notice them in your stools. The worms look like threads of white cotton about one centimetre long.

Severe or persistent threadworm infections can cause:

  • loss of appetite
  • weight loss
  • skin infection around the anus, if bacteria enter any scratches caused by itching (wearing cotton gloves while sleeping may help prevent this)
  • difficulty getting to sleep or staying asleep (insomnia)
  • bedwetting

In extremely rare cases, threadworms can spread outside the intestine to places such as the vagina or womb (in girls or women), the urinary tract and the liver.

Seeking medical help

If you suspect that you or your child may have threadworms, speak to your pharmacist about treatment.

See your GP if you think you have threadworms and you:

  • are pregnant or breastfeeding
  • your child has threadworms and they are under two

Read more about treating a threadworm infection.

Page last reviewed: 28/08/2013

Next review due: 28/08/2015