Expert reviewer Dr Adrian Raby, General Practitioner
Next review due June 2021

Chickenpox is a highly contagious viral infection that spreads easily from person to person. It causes an itchy rash with small blisters and can make you feel unwell.

A father and son sitting on the couch having a cuddle

About chickenpox

Chickenpox is a common infection caused by the varicella zoster virus. Children under 10 years are most likely to catch chickenpox, but you can be affected at any age. The chickenpox virus is spread through the air when you cough or sneeze or if you touch infected surfaces or blisters. If you’ve not had chickenpox before and someone in your household gets it, it’s very likely you’ll catch it too. You can catch chickenpox at any time of the year, but the infection is most common in the spring months.

Chickenpox causes a very itchy rash with small blistery spots. The spots start off flat and then become raised and blistered, before crusting over. Chickenpox can also make you feel very unwell. For most people though, chickenpox isn’t serious. You’ll probably feel better after a week or so.

The infection may be more serious if you’re very elderly, have a weakened immune system and in pregnant women and newborn babies. Adults are also more likely to have complications. See our Complications section for more information.

If you didn’t have chickenpox when you were a child, you can catch it as an adult if you’re exposed to the virus. But once you’ve had chickenpox, you’re very unlikely to catch it again. About nine out of 10 adults are immune because they caught chickenpox when they were a child.

If you’ve had chickenpox, the varicella zoster virus will stay in your body for the rest of your life. This doesn’t cause any symptoms or do you any harm. But sometimes the virus begins to reactivate (wakes up), usually in later life. This can trigger shingles, which causes a rash and nerve pain. You can catch chickenpox from someone with shingles if you haven’t already had chickenpox, but not the other way round.

Chickenpox quiz

Do you know how you catch it, who is most likely to get it, and is there a vaccine? Take the quiz to find out...

Symptoms of chickenpox

If you catch the chickenpox virus, you’ll begin to get symptoms 10 to 21 days later. The first symptoms may include:

  • mild headache
  • raised temperature (fever)
  • loss of appetite
  • nausea
  • a general feeling of being unwell

A day or two after your first symptoms, you’ll get a rash with flat or slightly raised red spots. You’ll probably notice them on your face and chest first. The spots may spread to your arms and legs and appear in patches or ‘crops’. You may also get spots in your mouth, nose and genitals.

Image showing boy with chickenpox

Your spots may become filled with fluid, forming small blisters. These can be extremely itchy and will usually crust over within a few days, forming scabs. Your spots will probably take around two weeks to heal completely. They don’t usually leave a scar, unless they get infected. This may be more likely if you scratch them.

Image showing chickenpox blisters
Chickenpox blisters

Chickenpox symptoms vary from person to person and tend to be worse in adults. It’s possible for young children with chickenpox to have very few symptoms. Some children may have only a few blistered spots, but others will have spots all over their body. Adults are more likely to have worse symptoms and develop complications. You may have a fever for longer or you may become more unwell.

If you have a young child, look out for signs of high fever and dehydration, as this could mean your child has a bacterial infection. Signs of dehydration include weeing less, feeling very tired and cold fingers and toes. Your child’s skin may also be less elastic, which means it won’t bounce back if you pull it slightly. If your child shows these signs, call a doctor straightaway.

Some of the symptoms mentioned above can be caused by other things such as another viral or bacterial infection or some types of skin conditions. So, if you’re unsure about whether you or your child has chickenpox, call your doctor’s surgery.

Diagnosis of chickenpox

You’ll probably be able to tell that you have chickenpox because it causes such a distinctive rash. If you know you’ve recently been in contact with someone who has chickenpox, this can help to confirm your diagnosis. But if you’re not sure about your symptoms, you feel particularly unwell or if you're pregnant or have a weak immune system, contact your GP.

Chickenpox is highly contagious. If you think you have the infection, you should try to keep away from young babies, pregnant women (or women of child bearing age) and anyone with a weak immune system. So it’s best to let your GP (or whoever you speak to on the phone at your surgery) know that you may have chickenpox. If you need to be seen, they may want to keep you away from other patients. So, they may ask you to wait in a different room to their usual waiting room. This is to make sure you don’t pass the infection on to anyone who’s at a higher-than-normal risk of complications from chickenpox.

Self-help for chickenpox

Most people with chickenpox get better without any specific treatment. They just use self-help measures and pharmacy medicines to ease their symptoms (such as high temperature or itchy rash). Sometimes though, doctors prescribe anti-viral medicines or special antibody injections for people who are most likely to develop complications.

If you have chickenpox, the following tips may help to ease your symptoms.

  • Drink plenty of fluids.
  • Make sure you’re not too hot or too cold. Wear layers so you can take clothes off (or put them on) if you need to.
  • Wear smooth, cotton fabrics that are less likely to irritate your rash.
  • Keep your nails short to stop you damaging your skin if you scratch it.
  • Chickenpox spots are usually very itchy, but try not to scratch them as this can make them infected.

If your skin is very itchy in places, you may be able to soothe it with calamine lotion. You can buy this lotion from a pharmacy without a prescription. Calamine lotion can dry out your skin though, and it stops easing the itching once the lotion dries on your skin. You may find that moisturising emollient creams and ointments can ease the itching too.

You can take paracetamol if you have any pain or a fever that’s bothering you. Children can take junior paracetamol (such as Calpol), as long as it’s suitable for their age and you stick to the recommended dose. You shouldn’t take non-steroidal anti-inflammatory drugs (such as ibuprofen) for chickenpox. This is because these medicines (called NSAIDs) may cause a serious skin infection in children and adults with chickenpox. Always read the patient information leaflet that comes with your medicine. If you have any questions, ask your pharmacist for advice.

If you’re very itchy, you can take an antihistamine, such as chlorphenamine (eg Piriton ®). These antihistamine tablets can be bought over the counter from a pharmacy but may make you feel sleepy. They are suitable for children over the age of one year.

If your symptoms seem to be getting worse, or you start feeling very unwell, contact your GP.

Anti-viral medicines for chickenpox

If you’re over 14 years and it’s been less than 24 hours since your chickenpox spots started to appear, you may be offered an anti-viral drug called acyclovir (Zovirax). This is particularly important if your chickenpox is severe or you’re at risk of getting complications, for example if you smoke.

Taking anti-virals within 24 hours of your rash first appearing may help to reduce your symptoms and mean you recover faster. As with all medicines, acyclovir can cause some side-effects, such as diarrhoea and vomiting. Speak to your pharmacist or GP for more information.

If you have a weakened immune system and haven’t yet had chickenpox and are exposed to someone with the infection, speak to your GP straightaway. You should also do this if you’re pregnant or have a very young baby and neither of you have already had chickenpox. You may be offered an injection containing varicella zoster antibodies – this is called a varicella zoster immunoglobulin (VZIG) injection.

Antibodies are proteins that help your immune system to fight bacteria and viruses. For the VZIG injection to work, you’ll need to have it within 10 days of coming into contact with someone who has chickenpox. This antibody treatment is known as passive immunisation, and is different to having a vaccination. The antibodies are unlikely to stop you having chickenpox, but they may make your symptoms milder. You may also be given an anti-viral medicine.

Causes of chickenpox

Chickenpox is caused by the varicella zoster virus. It’s highly infectious and is spread easily in tiny droplets in the air or by touching infected surfaces or blisters. If you didn’t catch chickenpox when you were a child, you can catch it as an adult.

The chickenpox virus is the same virus that causes shingles in adults. Once you’ve had chickenpox, the virus stays in your body. If it’s reactivated (woken up) again, usually when you’re older, this can cause shingles infection.

You can’t catch shingles from someone with chickenpox. But you can catch chickenpox from someone with chickenpox or shingles, if you haven’t already had chickenpox.

You usually get chickenpox symptoms between 10 and 21 days after you were first infected by the virus. You’re most infectious in the one or two days before your rash appears. You can catch the virus from someone with chickenpox from that time up until their spots crust over (about five to six days after their rash appears).

Complications of chickenpox

Complications of chickenpox are rare. If you're generally healthy, chickenpox is usually a mild infection and it’s unlikely you’ll have serious problems.

Complications are more likely to affect adults than children. Chickenpox can also be more serious for pregnant women, newborn babies or people with a weakened immune system. Your immune system may be weaker if you have HIV/AIDS, have had an organ transplant or are taking certain medicines. Older people, people who smoke, those taking steroids or those with cancer are also at a higher risk of complications.

Sometimes the chickenpox rash or spots get infected with bacteria. This is more common in children and if you scratch your spots. Chickenpox spots can leave scars, especially if they become infected. Signs of a bacterial infection include a high temperature (fever) and redness and pain around the chickenpox spots.

Chickenpox can cause a lung infection (pneumonia) or an infection of the brain (encephalitis). You’re more likely to get pneumonia if you smoke or are pregnant. If you get any of these complications, you may need to stay in hospital for treatment.

At any time later in life, the varicella zoster virus can be reactivated. If this happens, you’ll develop shingles. Shingles causes a blistering rash that appears in patches and can be very painful.

Prevention of chickenpox

If you haven’t had chickenpox, you can catch the infection from someone with chickenpox or shingles.

If you have chickenpox, it’s best to avoid contact with anyone else unless they know you have the infection. It’s particularly important to stay away from pregnant women (or women of child bearing age), newborn babies and those with a weak immune system. So, stay away from public places, work and your GP surgery, if possible.

Keep your child off school or nursery for five days from when the rash first appears or until the spots have all crusted over. You should avoid public transport too and should delay any travel (including flights) until you and your child are no longer contagious. Airlines have a right to refuse you if you’re unwell, and you shouldn’t travel if you have chickenpox until all your spots have crusted over. This is because they have a duty to protect other passengers.

There’s a vaccine that helps to prevent chickenpox, but it’s only recommended for certain people. You may be offered it if you’re a healthcare worker or regularly come into contact with anyone with a weak immune system. See our FAQ: Is there a chickenpox vaccine? for more information.

Chickenpox and pregnancy

If you’re pregnant and have had chickenpox, or you’ve been vaccinated, it’s unlikely to matter if you come into contact with someone who has chickenpox. But if you’ve never had chickenpox or aren’t sure, see your midwife or GP as soon as possible. You can have a blood test to find out whether you’re immune (this checks to see if you already have antibodies to the chickenpox virus).

If you’re not immune, you may be advised to have antibody treatment (called varicella zoster immune globulin) to help protect you. This can work up to 10 days after you come into contact with someone with the virus. So, see your midwife or GP as soon as possible if you think you’ve been exposed to chickenpox.

If you develop any rash during pregnancy, it’s a good idea to contact your midwife or GP too.

If you have chickenpox, your doctor may prescribe an anti-viral medicine – acyclovir – to help ease your symptoms. See our section on anti-viral medicines for more information. You’ll usually need to be more than 20 weeks pregnant to have this medicine, and take it within 24 hours of your spots appearing. Your doctor will discuss the risks and benefits of this medicine with you, so be sure to ask any questions.

Women who are pregnant are more likely to get complications from chickenpox, such as pneumonia. So, if you have chickenpox and develop symptoms of a chest infection (such as shortness of breath, chest pains or coughing), see your GP.

Chickenpox in the first half of pregnancy

Catching chickenpox in the first trimester (12 weeks) of pregnancy doesn’t seem to increase the chance of having a miscarriage. But if you’re not immune to chickenpox and catch it during the first 28 weeks of your pregnancy, there’s a small risk it could affect your baby.

You may be given an injection of antibodies, called varicella zoster immune globulin, to help fight the chickenpox virus. This doesn’t always stop you having chickenpox, but it can make your symptoms milder. You can have the injection up to 10 days after you come into contact with chickenpox and before any symptoms appear. It doesn’t work if you already have the chickenpox rash.

Chickenpox in the second half of pregnancy

If you get chickenpox late in your pregnancy, especially around the time you give birth, your baby could get chickenpox too. You may be offered an anti-viral medicine called acyclovir.

Contact your GP or seek urgent medical advice from your midwife or health visitor if you get chickenpox within a week of giving birth. Your baby can be given injections of antibodies to help protect them against the infection.

If you have chickenpox and want to breastfeed, ask your midwife or health visitor for advice. If you have a chickenpox spot near a nipple, don’t breastfeed from that side (express and throw away the milk).

Frequently asked questions

  • If you have chickenpox, you’re most infectious from one or two days before your rash appears. You can pass chickenpox on to other people until all your spots have crusted over. This usually happens around five or six days after your rash first appears.

  • You shouldn’t travel by plane until you’re no longer infectious, which is when all your spots have crusted over. This is usually around five days after the chickenpox rash appears for the first time. So, if you’ve already booked a flight, you may need to delay it for a few days.

    Airlines have a right to refuse you if you’re unwell, as it’s their duty to protect other passengers. This is because you could pass on the infection to other people. Chickenpox can be particularly dangerous for some groups of people, such as pregnant women, young babies and those with a weak immune system.

  • If you have chickenpox, try to stay away from people who haven’t had the infection before, especially anyone prone to complications. This includes pregnant women, newborn babies and anyone with a weakened immune system. Stay away from places where you’re most likely to be in contact with them, such as hospitals, GP surgeries and other public areas.

    If you do need to see any family or friends, tell them in advance that you have chickenpox so that they can stay away if they want to. You’re most infectious from one or two days before the rash appears until all your spots have crusted over.

  • There is a chickenpox vaccine, but in the UK it’s only recommended for certain people. This includes healthcare workers and anyone in regular close contact with someone who has a weak immune system if they’re not immune already.

    Vaccines work by stimulating your immune system to produce antibodies (which fight bacteria and viruses). The chickenpox vaccine (called Varilrix or Varivax) contains a small amount of a weakened form of the varicella zoster virus that causes chickenpox. If you have the vaccine, your body will ‘learn’ how to fight the virus, meaning you’re very unlikely to get chickenpox in the future.

    There are no plans for the chickenpox vaccine to be given routinely to all children in the UK. But your child may be offered it as a precaution if they could pass an infection on to someone who’s prone to complications. So, for example, if you’re having chemotherapy, your children may be given the vaccine if they haven’t had chickenpox already. This means there’s less chance of them catching chickenpox at school, nursery or a playgroup, and then passing it on to you.

    The chickenpox vaccine isn’t suitable for people who have a weak immune system. It’s given as two injections one to two months apart. If you’re due to have the vaccine but you’re ill, wait until you feel better before getting it.

  • Once you’ve had chickenpox, it’s likely you’ll stay immune for life. This means you’re unlikely to catch the infection again and won’t spread it to others. If people do have chickenpox again, this is usually because their first infection was very mild.

    Once you’ve recovered from chickenpox, the virus stays hidden in your body. This doesn’t usually cause any symptoms. But at any time later in life, the virus can be reactivated, causing shingles. If you have shingles, you can pass the virus to other people, causing them to develop chickenpox if they haven’t already had the infection. But you can’t catch shingles from someone with chickenpox. You also can’t have shingles without having chickenpox first, even if it was years earlier.

Did our information help you?

We’d love to hear what you think. Our short survey takes just a few minutes to complete and helps us to keep improving our health information.

About our health information

At Bupa we produce a wealth of free health information for you and your family. This is because we believe that trustworthy information is essential in helping you make better decisions about your health and wellbeing.

Our information has been awarded the PIF TICK for trustworthy health information. It also complies with the HONcode standard and follows the principles of the The Information Standard.

The Patient Information Forum tick  This website is certified by Health On the Net Foundation. Click to verify.

Learn more about our editorial team and principles >

Related information

  • The Royal College of Obstetricians and Gynaecologists have information on chickenpox and pregnancy. Visit for more information.

    • Chickenpox. Clinical Knowledge Summaries., last revised October 2016
    • Chickenpox. The MSD Manuals., last full review/revision February 2018
    • Chickenpox. PatientPlus., last checked November 2016
    • Varicella-Zoster virus (VXV). Medscape., updated February 2018
    • Shingles. Clinical Knowledge Summaries., last revised December 2016
    • Chlorphenamine maleate. NICE British National Formulary., last updated April 2018
    • Aciclovir. NICE British National Formulary., last updated April 2018
    • Immune system anatomy. Medscape., updated November 2013
    • Chickenpox treatment and management. Medscape., updated April 2017
    • Passenger health FAQs. Civil Aviation Authority., accessed May 2018
    • Pregnancy. Oxford Handbook of General Practice (online). Oxford Medicine Online., published online April 2014
    • Chicken pox in pregnancy. Royal College of Obstetricians and Gynaecologists. January 2015.
    • Immunity and how vaccines work. The Green Book. Public Health England. 2013., accessed May 2018
    • Varicella vaccine. The MSD Manuals., last full review/revision November 2014
    • Varicella. The Green Book. Public Health England. 2015., last updated August 2018
  • Reviewed by Laura Blanks, Specialist Health Editor, Bupa Health Content Team, June 2018.
    Expert reviewer Dr Adrian Raby, General Practitioner.
    Next review due June 2021