Autism is a condition that affects brain development, which means that the brain develops in a different way from other people. There are different types of autism including atypical autism and Asperger's syndrome. This information covers all types of autism.
Although autism affects people in different ways, the main symptoms are:
finding it hard to deal with social situations, such as understanding other people's emotions, expressing one's own feelings and thoughts, and maintaining eye contact; some people with autism may prefer to be on their own
having difficulties with speech and communicating with other people, responding to their facial expressions or tone of voice, and understanding common sayings; some people with autism may have limited speech or prefer to communicate with sign language
having narrow interests or obsessions, repeating routines or movements (such as rocking) or finding it hard to prepare for change or plan for the future
being under- or over-sensitive to sound, light, colour, smell and taste (called sensory sensitivity).
Although autism is a lifelong condition, some adults with autism are able to live fairly independently. Others may also have a learning disability and need support and care throughout their lives. Some people with autism may also have other difficulties, such as a mental health problem (see 'What treatments should I be offered if I also have a mental health problem?') or they may behave in a way that other people find challenging (see 'What support should I be offered for challenging behaviour?').
This information uses the word 'autism', but there are other terms that different people prefer to use, for example autism spectrum disorder, autistic spectrum condition, autistic spectrum difference and neuro-diversity.