First of all, yes it is common. I work in healthcare and I see clubbing fingernails on a daily basis and 95% of the time it's patients that have been smoking for a long time and they probably have some underlying emphysema or COPD. So yes, smoking does cause clubbing as its the primary health problem that causes the respiratory problems. It is a secondary sign of peripheral hypoxia. Youre jumping to the worst case scenario as to what could be wrong when its most likely attributed to the simplest answer as he is holding a cigarette in the posted picture. So when you hear hoofbeats think horses, not zebras.

So no I'm not spreading misinformation nor am I being selfish and "just want to be heard" I'm telling what is most likely the case. And if this were actual medical advice and if the guy in the picture was actually the one that posted it, this would be different. But clearly you just googled "clubbing fingernails" read the worst underlying conditions and decided you are an expert now. Clearly you don't know what an "urgent matter" is either because otherwise this guy wouldn't be Cally sitting smoking a cigarette in the pic.

Oh and if you want people to respect your opinion and have civil discussions, maybe don't call people "retarded" and a "fucking idiot." I don't come to your burger king and tell you when to take the fries out of the dryer so don't imply you know what you're talking about with his medical situation.