They can, but often they don't. Most medical conditions do not make you inadmissible. Concerns arise mainly around public health risks or conditions expected to place excessive demand on services, and exemptions exist. A police certificate is required from countries where you've lived long enough; if one is genuinely impossible to get, submit proof of your efforts and a letter of explanation rather than leaving it blank. Never hide a condition or a record; honesty is always the safer path.
Updated July 2026