There is some confusion around the responsibilities of the employer and candidates as regards the asking, and disclosing of health related questions when you are applying for a job role.
The Equality Act came into force on October 1st 2010 and was introduced to basically protect people from discrimination in the workplace and in wider society. This single Act replaced the previous legislations including the Sex Discrimination 1975, Race Relations 1976 and Disability Discrimination Acts 1995.
Relating to recruitment the Equality Act protects candidates inasmuch as they cannot be discriminated against for health reasons when applying for a position. Before the Equality Act came into force it was common for employers to ask candidates to complete a health questionnaire and this usually took the form of questions about the general state of their health and fitness and even in some cases asked about illness and diseases which were unrelated to the job in question.
The Government took the view that candidates were not being interviewed or offered jobs because of information in these questionnaires even if that information was unrelated to their ability to do the job. To solve this the employer is now no longer allowed to ask such questions at interview time nor request the completion of such questionnaires until the point where the candidate was offered the job. This ensured that health, fitness or any disability played no part in the decision making.
Only when you have been offered a job, with or without conditions, can an employer ask questions about your health or any disability you might have. Incidentally, please note, just by asking about your heath at interview time the employer doesn’t actually commit an offence but any action subsequent to that might deem their actions discriminatory.
There are of course exceptions to the above. Questions about health and/or disability may be asked if the candidate needs specifics at the interview stage, or to take part in an assessment phase of the interview process, or indeed their ability to carry out fundamental tasks intrinsic to the job in question.