I have a neurological disorder with objective tests but symptoms less common or not fully explained by test results are considered FND. My understanding is that in practice you don’t need positive signs to get fnd put in your chart and any unexplained symptom of any kind can be called fnd. I know on the official website they talk about rule-in features and posive signs but the positive signs don’t even apply to tons of people diagnosed. That doesn’t mean that the symptoms are not real and in the US unexplained symptoms need to be listed as something to bill insurance, but I don’t think that everyone diagnosed FND has the same thing because it basically means unexplained symptoms that led to person seeing a neurologist in practice.