How To Kill Head Lice Fast

How To Get Rid Of A Head Lice Infection

How To Get Rid Of A Head Lice Infection

The head louse (Pediculus humanus capitis) is in the order of Psocodea, it is an ectoparasite that lives exclusively on the head of humans. An adult head louse is about 2 to 3 millimeters in length and must feed on blood several times a day to survive; it will lay its eggs at the bottom of the hair shaft allowing it to remain close to the scalp and maintain a constant temperature for the eggs to hatch.


The most viable eggs are those laid within six millimeters of the scalp

Life Cycle Of A Head Louse

the life cycle of a head louse

There Are Three Main Stages In The Life Cycle Of A Head Louse: Egg, Nymph And Adult.


What we call nits are actually head lice eggs which are laid by the adult female and attached to the base of the hair shaft, they remain attached for around 6 to 9 days before hatching. A nit is around 0.8 millimeters by 0.3 millimeters, white to yellowish and oval in shape, they are often mistaken for dandruff.


When the egg hatches it releases a nymph which looks like an adult louse, only it is the size of a pin head, the nymph takes around 7 days until it becomes an adult. After the nymph is hatched the egg shell turns to a dull yellow color and remains attached to the hair shaft.


The adult louse has six legs with strong claws for gripping and moving, it is around the size of a sesame seed and is grayish white to tan in color. The female is generally larger than the male and can lay up to 8 eggs per day.


  • An adult louse can live up to 30 days on a human head, but off the head, or without blood meals will die within 1 to 2 days
  • If a nit (egg) is not kept at the same temperature that is found close to the scalp, they cannot hatch and will die within a week

How Do You Catch Head Lice?

The Common Way To Catch Head Lice:

A head lice infestation has nothing to do with personal hygiene or the cleanliness of their environment. The most common way of getting head lice is to have direct, head to head contact with a person who has head lice – (head lice cannot jump or fly, they can only crawl)


The Uncommon Ways To Catch Head Lice

  • Wearing clothing after a person with head lice has worn it. For example, hats, scarves, or any clothing that must be pulled over the head such as a jumper or t-shirt.
  • Using brushes, combs or towels after a person with head lice has used them
  • Lying on a couch, bed, pillow, carpet or stuffed animal etc that has very recently been in contact with a person who has head lice

Head Lice Symptoms

It is not uncommon for a head lice infestation to be asymptomatic (no symptoms), especially if it is the first infestation or the infestation is light.

General symptoms are things like:

  • Itching (caused by an allergic reaction to the louse bite)
  • Feeling the louse moving in your hair
  • Sleeplessness and irritability
  • Head sores caused by scratching (may become infected)


If one member of the family has an active infestation it is important to check all other members of the household and treat accordingly. Alternatively you may treat the entire household at the same time, both as a treatment for the infected and as a preventative measure for the others.

Over The Counter Medication

There are many over the counter medicines that kill lice but not all are the same. Some have the ability to kill the eggs (ovicidal effect), and some don’t.

If you choose to use a medication which has a very weak ovicidal effect or none at all, you will need to routinely retreat. If you choose a medicine with a strong ovicidal effect you will only have to retreat if there are still active lice present a few days after treatment.


  • If you do have to retreat it should be done after all of the eggs have hatched but before any new eggs can be produced
  • Do not wash your hair with shampoo or conditioner before applying the medication, and do not wash your hair for one to two days after you have removed the medication
  • If there are still some lice present after 10 to 12 hours, but they appear to be moving very slowly, do not retreat. The medication may require more time to be effective. Use a nit comb and remove any lice, both alive and dead from the hair
  • After 10 to 12 hours, if all of the lice appear to be still alive, it probably means that the medication is not working. DO NOT RETREAT, talk to your pharmacist or health care provider and try a different medication

Other Treatments

  • Lice will die when exposed to temperatures higher than 53.5°C (128.3°F) for more than five minutes, so you can machine wash any items used within two days before the treatment such as hats, scarves, towels and bedding etc in hot water and dry them in a clothes dryer on the hot cycle to help get rid of the infestation
  • Soak combs and brushes in hot water higher than 53.5°C (128.3°F) for 10 to 15 minutes
  • Vacuum the floors and furniture where a person with head lice has been lying – This is just a precautionary measure, it is very rare to catch head lice from furniture or carpet.


Do not use household sprays to get rid of head lice, they may be toxic if inhaled or absorbed through the skin

How To Prevent And Control Head Lice

To prevent and control head lice you must:

  • Avoid head to head contact
  • Do not share clothing with a person who has head lice
  • Do not share brushes, combs or towels etc with a person who has head lice
  • Do not lie on a bed, couch, carpet or stuffed animal etc after a person with head lice hast had contact with them
  • Machine wash in hot water all washable items that a person with head lice has had contact with up to two days before treatment. If you have a clothes dryer you can dry all of these items on the hot cycle to further help eradicate the lice