Head lice are tiny insects that live in hair. Nits are the empty egg cases attached to hair that head lice hatch from.

Head lice are a common problem, particularly in school children aged 4-11.

They're largely harmless, but can live in the hair for a long time if not treated and can be irritating and frustrating to deal with.

This page covers:

Spotting head lice

Getting rid of head lice and nits

How you get head lice

Prevention

How to spot head lice

Head lice can be difficult to spot, even when the head is closely inspected.

They're very small whitish or grey-brown insects that range from the size of a pinhead to the size of a sesame seed.

The only way to be sure someone has head lice is to find a live louse by combing their hair with a special fine-toothed comb. This is called detection combing.

Less reliable signs of head lice include:

• small white eggs or nits (egg cases) in the hair behind the ears or at back of the neck – see image above
• an itchy scalp
• a rash on the back of the neck
• feeling as though something is moving in the hair

How to get rid of head lice and nits

Treatments to get rid of head lice are available to buy from pharmacies, supermarkets and online. You don't usually need to see your GP.

The main treatments are:

• lotions or sprays that kill head lice – these can be very effective, but some aren't suitable for pregnant or breastfeeding women, or for children under two
• removing head lice with a specially designed comb – this is suitable for everyone and relatively inexpensive, but needs to be repeated several times and can take a long time to do thoroughly

A pharmacist can advise you about the treatments available if you're not sure which is best for you or your child.

Make sure you carefully follow the instructions that come with the treatment you choose.

Read more about the treatments for head lice.

How you get head lice

Head lice are spread by direct head to head contact. They climb from one person's hair to another's.

Head lice:

• can't fly, jump or swim
• are very unlikely to be spread by objects such as hats, combs and pillows
• don't have a preference for dirty, clean, short or long hair
• only affect people and can't be caught from animals

Once detached from the hair, head lice will usually die within 12-24 hours.

Preventing head lice

It's very difficult to prevent head lice.

You may want to consider regular detection combing – for example, on a weekly basis – if you're concerned about your children or yourself.

Lotions and sprays don't prevent head lice and should only be used if a live louse has been found in your or your child's hair.

Staying off work or school and washing clothing and bedding on a hot wash is unnecessary, as it's unlikely to help prevent the spread of head lice.

The only way to be certain that you or your child has head lice is to find a live louse.

Spotting head lice in hair can be very difficult, so it's best to try to comb them out with a detection comb.

Detection combs are special fine-toothed plastic combs that you can buy from your local pharmacy, supermarket or online. A comb with flat-faced teeth and a tooth spacing of 0.2-0.3mm is best.

Detection combing can be carried out on dry or wet hair. Dry combing takes less time, but wet combing is more accurate because washing with conditioner stops head lice moving.

Wet detection combing

To use the wet detection method:

• Wash the hair with ordinary shampoo and apply plenty of conditioner.
• Use an ordinary, wide-toothed comb to straighten and untangle the hair.
• Once the comb moves freely through the hair without dragging, switch to the louse detection comb.
• Make sure the teeth of the comb slot into the hair at the roots, with the edge of the teeth lightly touching the scalp.
• Draw the comb down from the roots to the ends of the hair with every stroke, and check the comb for lice each time – remove lice by wiping the comb with tissue paper or rinsing it.
• Work through the hair, section by section, so that the whole head of hair is combed through.
• Do this at least twice to help ensure you haven't missed any areas and continue until you find no more lice.

If you find head lice, you should check the rest of your family. Treat everyone found to have head lice on the same day.

Read more about how to get rid of head lice.

Dry detection combing

To use the dry detection method:

• Use an ordinary, wide-toothed comb to straighten and untangle the hair.
• Once the comb moves freely through the hair without dragging, switch to the louse detection comb.
• Make sure the teeth of the comb slot into the hair at the roots, with the edge of the teeth lightly touching the scalp.
• Draw the comb down from the crown to the ends of the hair with every stroke.
• Look for lice as the comb is drawn through the hair. If you see a louse, trap it against the face of the comb with your thumb to stop if being repelled by static electricity.
• Comb each section of hair three or four times before moving on to the next section, until the whole head has been combed through.

If you find head lice, you should check the rest of your family. Treat everyone found to have head lice on the same day.

Read more about how to get rid of head lice.

Treatments to get rid of head lice are available to buy from pharmacies, supermarkets and online. 

The main treatments are:

Lotions and sprays

Wet combing

Everyone with head lice in your household should be treated on the same day.

If a treatment doesn't work the first time, you can try it again, try a different treatment, or get advice from your school nurse, health visitor, pharmacist or GP.

Lotions and sprays

There are several different products that can be applied to the scalp and hair to kill head lice, including:

• dimeticone 4% lotion or lotion spray – applied and left for 8 hours (usually overnight)
• dimeticone 4% spray gel – applied and left for 15 minutes
• mineral oil and dimeticone spray – applied and left for 15 minutes
• isopropyl myristate and cyclomethicone solution – applied and left for 5-10 minutes

Some treatments need be done twice – seven days apart – to make sure any newly hatched lice are killed.

Detection combing should usually be done two or three days after finishing treatment, and again another seven days after that, to check for any live head lice.

Always check the pack or leaflet to see if a product is suitable for you, particularly if you're pregnant or breastfeeding, or your child has head lice and is less than two years of age.

Your pharmacist can recommend a suitable treatment and advise you how to use it correctly if necessary.

Wet combing

Wet combing involves removing head lice with a special fine-toothed comb. It's suitable for everyone and is relatively inexpensive.

A number of lice removal combs are available to buy. Combs with flat-faced teeth spaced 0.2-0.3mm apart are best for removing head lice, although combs with smaller gaps can be used to remove eggs and nits (egg cases) after treatment.

The comb may come with instructions outlining how to use it. A commonly used method is described below.

• Wash the hair with ordinary shampoo and apply plenty of conditioner.
• Use an ordinary, wide-toothed comb to straighten and untangle the hair.
• Once the comb moves freely through the hair without dragging, switch to the louse detection comb.
• Make sure the teeth of the comb slot into the hair at the roots, with the edge of the teeth lightly touching the scalp.
• Draw the comb down from the roots to the ends of the hair with every stroke, and check the comb for lice each time – remove lice by wiping the comb with tissue paper or rinsing it.
• Work through the hair, section by section, so that the whole head of hair is combed through.
• Do this at least twice to help ensure you haven't missed any areas, until no more lice are found.

Repeat this procedure on days five, nine and 13. Detection combing  should be done on day 17, to check for any live head lice.

Treatments not recommended

The following treatments aren't recommended because they're unlikely to be effective:

• products containing permethrin
• head lice "repellents"
• electric head lice combs
• tree and plant oil treatments, such as tea tree oil, eucalyptus oil, and lavender oil
• herbal remedies

There's also no need to stay off work or school or wash clothing and laundry on a hot wash, as this is unlikely to be useful.