It depends a bit on the employer. If they ask about it on a pre-employment medical questionnaire or examination, you shouldn't try to conceal it. There are usually disclosure clauses, which you sign, which may provide for disciplinary action or dismissal if you have been found to have made a false statement. If the condition doesn't affect your ability to do your job, and your job doesn't have an adverse affect on your condition, it shouldn't be a problem. A supportive report from a specialist wouldn't hurt.
Cheers,
ausdoc