1. Refusing to provide clarification to previously provide medical leave note upon employer's request. Your employer might not be clear about the reasons for you inability to report to work and could ask you to go back to your doctor and get clarification in a form of additional medical note. Many employees immediately reject that type of request on the grounds of medical confidentiality and privacy. In many cases, this is a mistake and a fight simply not worth fighting. Your employer is entitled to have basic information about the reasons for your inability to report to work. While they may not be entitled to see your medical records or know your exact diagnosis, at they have the right know what physical limitations prevent you from working. Employee often insist on not providing this information and end up getting fired where it was so easy to avoid by simply giving the employer what they need, assuming that their request is reasonable.
2. Proving a medical leave note that directly or implicitly suggests that the duration of the needed leave is unclear. Under the law, an employer doesn't have to provide leave of indefinite duration, and in most cases an employer can safely terminate an employee, where it looks like that employee might not ever come back to work. Therefore, if you intent to return to work, you should make sure that you medical note has your date of return to work with or without restriction, or at least an anticipated date of return, even if you / your doctor is not 100% sure that you will be able to start working again on that day.. Later, you may have the option to extend your leave. You should not rely on your doctor to write your medical leave note the right way, and you should definitely read it yourself before passing it to your employer. You cannot expect your doctor to know your legal rights. Your doctor's specialty is medicine; not disability laws.
3. Being tough and trying to work through pain. In the video below, I talk about how being tough and trying to work through pain can lead to problems at work: