Autism may be a more familiar word these days, but misunderstanding about the condition is still rife. As World Autism Awareness Day approaches, Lisa Salmon hopes that will change.

If a new colleague seems unfriendly, sticks rigidly to a routine and doesn't get your sarcastic jokes, don't immediately dismiss them as weird. They may be autistic.

Around one in every 100 people is on the autistic spectrum and has difficulties in social situations, but loves order and routine, and yet the condition is still poorly understood.

World Autism Awareness Day (April 2) hopes to improve both the public and organisations' understanding of autism, and highlight the fact that it's not just a childhood problem.

Carol Povey, director of the National Autistic Society's (NAS) Centre for Autism, says: "Children with autism grow into adults with autism - it's a lifelong condition.

"If people haven't got someone in their family with autism, there will be a neighbour, someone in your child's class, or one of your colleagues.

"Autism is a spectrum condition and you will meet people with it in your daily life. You need to be able to understand it, listen to them and be supportive. It's hidden, and that's why it's hard for people to understand."

Autism is described as a spectrum disorder because, while everybody with it shares three main areas of difficulty - with social communication, social interaction and social imagination - the condition will affect them in very different ways and to varying degrees.

Some are able to live relatively normal lives, often trying to hide their difficulties, while others will need lifelong specialist support.

For instance, people with Asperger Syndrome, which is a form of autism, are often of average, or above average, intelligence and tend to have fewer problems with speaking than people with other forms. They don't usually have the learning disabilities associated with autism, but may have specific learning difficulties, such as dyslexia and dyspraxia, or other conditions including attention deficit hyperactivity disorder (ADHD).

The NAS explains that people with autism say that, to them, the world is a mass of people, places and events which they struggle to make sense of, and which can make them very anxious.

They may not understand the subtleties of the way people interact socially, or understand hierarchy, says Povey, and may not recognise things like irony and sarcasm; often people with autism will take things literally.

They may need more structure than other people, and Povey explains: "They like to know exactly what they have to do, and may be very good at details, and less good at tasks where they're reliant on social interaction."

People with autism can often contribute extremely well at jobs where a high level of precision, detail and the ability to focus over long periods of time is needed.

"It's things that are instinctive for people who don't have autism, even to the extent of knowing what space to put between yourself and other people, that often has to be learned by people with autism," says Povey. "That whole social milieu can be quite difficult and anxiety-provoking. A lot of people with autism report high levels of stress just to go through things that most people take for granted."

That stress can be particularly acute at work - although having autism can, in itself, hinder employment prospects.

According to the NAS, most of the 300,000-plus working-age adults with autism want to work, but are held back by a lack of understanding. As a result, only 15% are in full-time paid employment, and just 9% are working part-time .

Of those who have worked, around a third have experienced bullying and feel they've received unfair treatment or discrimination.

However, Povey says that once someone gets an autism diagnosis - something that can be a struggle, particularly as an adult - small changes at work, such as making tasks clearer, or taking breaks at a different time to colleagues, can make a major difference.

"It can also help to make staff aware that if their colleague appears a little different, it's because they're autistic, not because they're unfriendly," she says.

World Autism Awareness Day coincides with the publication of a revised adult autism strategy by the Government, which is expected to recommend an autism awareness programme and improvements in training about autism across all public services.

"One of the main things we're hoping to see is around the training of professionals, and general understanding about autism, which is still quite patchy," says Povey. "More understanding would make an enormous difference to the lives of people with autism, so they wouldn't have to always be fighting to get themselves understood."

One of the main champions in the fight to help improve understanding is Temple Grandin.

Despite not being able to speak until she was four years old, due to her own autism, an extensive early education programme and attending a school for gifted children led Grandin to a hugely successful career designing facilities for livestock, a PhD in animal science and honorary degrees from many universities.

In addition to her animal science successes, the 66-year-old American has been a very vocal campaigner for the welfare and rights of people with autism, and her new book, The Autistic Brain, is about to be published.

As well as offering new ways of understanding the causes, diagnosis and treatment of autism, she hopes the book will provide an insight into the different ways people with autism think.

Grandin, who describes herself as a "photo realistic visual thinker", says the worst thing about having autism for her was being bullied at school, and being called names like "tape recorder" because she repeated words to herself.

"I laugh about it now, but back then it really hurt," she remembers.

She says treatment for autistic children should start at the first sign of abnormal behaviour, and believes those at the higher end of the autism spectrum should be encouraged to get involved with peers in areas of common interest, typically music, art, robotics and cooking.

She stresses that at school, teachers need to work on developing autistic children's strengths, pointing out that people at the higher end of the spectrum often have uneven skills, so a child that's poor at reading, for example, may be very good at maths.

"A mistake educators make is to put too much emphasis on deficits, and not enough emphasis on talents and abilities," she says. "But people on the autism spectrum need to be taught social skills, like coaching an actor to be a character in a play."

Grandin, whose life was the subject of the award-winning 2010 film Temple Grandin, starring Claire Danes, stresses: "I'm worried that the educational system is going to block out some unique kinds of minds.

"When different kinds of minds work together, they can complement each other's skills and do great things."

What causes autism?

The exact causes are not known, although it's thought there's a genetic predisposition to the condition. Scientists think multiple genes are likely to be responsible, rather than a single gene, and the National Autistic Society says much more research is needed. There's strong evidence to suggest autism can be caused by a variety of physical factors, all of which affect brain development, however, the charity stresses that the condition is not due to emotional deprivation or bad parenting.

:: Onesie Wednesday

The National Autistic Society is holding Onesie Wednesday on World Autism Awareness Day (April 2), to help spread the message that 'it's OK to be different' and is encouraging people to organise onesie-themed fundraisers like a wear-a-onesie to work day or holding a bake sale using the NAS recipe for onesie gingerbread men. For a free Onesie Wednesday pack, visit www.autism.org.uk/onesiewednesday

:: The Autistic Brain By Temple Grandin is published by Rider on April 17, priced £9.99

(World Autism Awareness Day is Wednesday, April 2)