Autism spectrum disorder (ASD) is a condition that affects social interaction, communication, interests and behaviour. It includes Asperger syndrome and childhood autism.
The signs of ASD typically start to develop in childhood.
It's estimated about 1 in every 100 people in the UK has ASD. More boys are diagnosed with it than girls.
There's no "cure" for ASD, but a range of educational and behavioural support programmes can help people with the condition.
Read about help and support available for people with ASD.
Signs and symptomsPeople with ASD tend to have problems with social interaction and communication.
They can find it hard to understand other people's emotions and feelings, and have difficulty starting conversations or taking part in them properly. Language development may be delayed.
People with ASD are often only interested in certain things, have repetitive behaviours, and like to stick to a set routine. They tend to get upset if these routines are disrupted.
Children and young people with ASD frequently experience a range of cognitive (thinking), learning, emotional and behavioural problems. For example, they may also have attention deficit hyperactivity disorder (ADHD), anxiety, or depression.
About half of those with ASD have some degree of learning difficulty. However, many people are able to be independent with appropriate support.
Read more about the symptoms of ASD.
Getting a diagnosisThe main features of ASD – problems with communication and social interaction – can often be recognised during early childhood.
Some features of ASD may not become noticeable until a change of situation, such as when the child starts nursery or school.
See your GP or health visitor if you notice any of the signs and symptoms of ASD in your child, or if you're concerned about your child's development. It can also be helpful to discuss your concerns with your child's nursery or school.
Read more about diagnosing ASD.
Caring for someone with ASDBeing a carer isn't an easy role. When you're busy responding to the needs of others, it can affect your emotional and physical energy, and make it easy to forget your own health and mental wellbeing.
If you're caring for someone else, it's important to look after yourself and get as much help as possible. It's in your best interests and those of the person you care for.
Find out more about care and support, including information about:
Carers Direct helpline on 0300 123 1053.
What causes ASD?The exact cause of ASD is unknown, but it's thought several complex genetic and environmental factors are involved.
In the past, some people believed the MMR (measles, mumps and rubella) vaccine caused ASD, but this has been investigated extensively in a number of major studies around the world, involving millions of children, and researchers have found no evidence of a link between MMR and ASD.
Read more about the causes of ASD.
Autism in adultsSome people with ASD had features of the condition as a child, but enter adulthood without ever being diagnosed.
However, getting a diagnosis as an adult can often help a person with ASD and their families understand the condition, and work out what type of advice and support they need.
For example, a number of autism-specific services are available that provide adults with ASD with the help and support they need to live independently and find a job that matches their skills and abilities.