Teachers are concealing disabilities for fear of damaging their chances of getting jobs or promotions, new research suggests.
A study for the Disabled Teacher Taskforce (DTT) has found that some school staff with physical and mental problems are missing out on support because they are afraid to tell their bosses about conditions.
Disabled teachers also reported being discriminated against in their work, but are "frustrated" because it is difficult to prove.
The DTT, a cross-agency body of workforce representatives that is backed by the General Teaching Council for England (GTC), has called for more teachers to disclose their problems.
Those who are disabled are entitled to funding from the Government to help with the costs of equipment, transport or the salary of an assistant, but the research claims that many refuse to admit they have the problems that would make them eligible.
The findings are set out in a new report called Removing Barriers, Promoting Opportunities: shaping the future for teachers with disabilities in England, which is based on the experiences of more than 120 teachers.
The document says school staff have "mixed views and experiences". Those who reported their conditions said it had helped "improve relations" with colleagues, who were more supportive, but some wanted to "reserve their right to confidentiality".
"Others are more reluctant (to disclose their disability), believing that their previous job applications had suffered as a result, in some cases reporting they had more success at gaining a job interview by not disclosing their disability," the report says.
Those who have a "dilemma" about how to "present themselves" often have unseen disabilities - for example, mental health issues, dyslexia or other physical impairments that may be not be immediately obvious.
The report recommends that the GTC "support teachers to provide full disclosure of disability to the employer, promoting the benefits that a diverse workforce can bring to a school".
One NQT from Yorkshire interviewed for the research illustrated the problem. She currently has a temporary post. "Taking the decision to be honest on my application forms about my disability was a challenge, but didn't really work out due to a lack of interviews," she said.
"(However) I would still advise others to be honest about their disability at interview. Bring the subject up and be positive about it."
Tony Neal, chair of the DTT and of the GTC's policy and research committee, told The TES: "On the one hand, some teachers had positive experiences when disclosing their disability, and their employers made adaptations for them. But other teachers don't disclose because they worry about how their condition may be seen.
"We hope this report sends out a strong message that disclosure should be encouraged."
One teacher who hides part of her disability said this affects her relationship with colleagues.
"I only have part of my support package in place and it causes resentment from some staff, who do not understand why I have a PA, but it is my right not to have to share the reasons with them," she said.
CASE STUDY: `Be honest'
"Dionne" is a secondary teacher and head of physics at a school in Nottinghamshire.
"I have been teaching in the same school for more than 20 years. I have arthritis and now walk with the aid of a stick. I'm in pain all the time, which I try to manage with medication, but sometimes there are unpleasant side-effects, such as drowsiness.
"I disclosed my disability from the very beginning, as I didn't think it was fair on the school to do anything else. I would advise others in similar circumstances to be open and honest, otherwise it just creates a lot of problems further down the line.
"I'm lucky as this is a fantastic school that has been very supportive. Sometimes they may misunderstand what I need to help me, but their intentions are always good."