A special educational need is defined as a learning difficulty or disability that makes learning a challenge for a child.
Disabilities can include
Read the government guide to special education needs and disabilities (PDF 567KB)
Where are child has medical needs, read the government guide to supporting children with medical conditions (PDF)
there are also government templates for medical conditions (Word doc )
Other resources and guidance for children with medical conditions can be found on the government website
There is also a guide for schools in Hounslow on supporting children with medical needs