Discover how to craft a professional resignation letter due to illness. To help you draft your resignation letter like the example above, here's a checklist of what to include: What to include in a resignation letter.Due to health concerns, I must resign immediately. In this article, we'll give you practical tips, examples, and a resignation letter template to help you navigate the process with confidence and ease. Master the art of writing a resignation letter with our comprehensive guide, offering step-by-step instructions, tips, and templates. Say you left because of "resolved health issues", emphasis on resolved. Dear (name of manager),. Tips for writing resignation letters for health reasons, parts to include in the letter, and some sample letters.