The effect must be:

• Substantial (i.e. more than trivial)
• Adverse (i.e. unfavourable or injurious)
• Long-term (i.e. for at least a year or as long as a person lives)

This includes any physical or mental disability including sensory impairment.
It also covers disabilities such as mental illness, mental health problems, learning disability, autism, ADHD, asthma, dyslexia, diabetes, epilepsy, severe and challenging behaviour and children and young people with severe disfigurement. It also includes children and young people diagnosed with HIV, cancer and MS from the point of diagnosis.

Not all children with SEN are disabled under the terms of the Act, neither do all children with a disability have SEN.

The Special Educational Needs and Disability Act 2001 introduced new rights for disabled people in education and aims to further improve education provision for pupils with SEN. From September 2002 it has been unlawful for schools to discriminate against disabled pupils in their admissions and exclusions, education and associated services.

There are two main duties:

• Not to treat disabled pupils less favourably
• To make reasonable adjustments to avoid putting disabled pupils at a substantial disadvantage

There is a duty on Local Authorities and schools to prepare a written Accessibility Strategy for the schools for which they are responsible in relation to three key areas:

• Access to the curriculum
• Physical access
• Access to written information

In addition, from December 2006 (for secondary schools) and (December 2007 for primary schools) all schools are required to publish a Disability Equality Scheme showing how they meet the needs of disabled pupils at the school.