A delayed diagnosis may support a medical negligence claim, but not every delay is negligent. You would generally need evidence that the healthcare professional’s care fell below a reasonable standard and that this probably caused avoidable harm or worsened your condition. In England and Wales, the usual time limit is three years from the incident or the date you first reasonably knew the injury might be linked to negligence, although exceptions can apply; rules differ elsewhere in the UK. A solicitor regulated by the SRA can assess the evidence and limitation period.