This is a question that comes up fairly frequently. Many people aren’t sure what to do or say. The industry standard is that only licensed medical professionals or nail professionals qualified to an advanced standard that allows diagnosis and treatment of some conditions can properly diagnose a medical condition of the hand, and if a client’s hand is clearly not normal or healthy, then a medical professional is needed. If you attempt to diagnose the condition it would be a clear violation of the law in most countries. In the US, for example, federal law expressly forbids anyone, other than a licensed medical doctor or podiatrist from diagnosing any medical conditions of the nail, finger, hand or foot and for good reason. When it comes to these types of medical conditions, only medical doctors can diagnose, treat and prescribe any treatments. If we attempted to replace the doctor and provide our own opinions, we aren’t doing the right thing for the client. From any perspective legal, medical or moral, it is always best to instruct the client to see a medical professional before providing any nail salon services to unhealthy nails. That’s best for everyone concerned, especially the client.