Chickenpox is a highly contagious childhood infection caused by the varicella-zoster virus.
The condition causes a very itchy, blistery rash and usually a fever. The chickenpox virus spreads through the air, such as when an infected person sneezes or coughs. It can also be contracted through direct contact.
Chickenpox is most common in children under 10, although it can develop at any age. Outbreaks are most frequent in winter and spring, between March and May.
People who have had chickenpox almost always develop lifetime immunity (meaning you are extremely unlikely to get it again). However, the virus remains dormant in the body and it can reactivate later in life and cause shingles.
Find out more about the symptoms of chicken pox