There is perhaps no physical exam sign more enthused about by consultants and more bluffed by students than the jugular venous pressure (JVP). While initially I was not a believer, I have come recently to appreciate its usefulness. This epiphany did not occur without significant time spent perusing the literature and finally coming to understand what the JVP does and does not tell you.
The first point to make abundantly clear is that JVP is simply a surrogate for central venous pressure (CVP). This roughly estimates the right atrial pressure. The obvious first question a sceptic would ask is how good a job it does at this?
Well, if we refer to the JAMA rational clinical exam series from 2009 (1), a systematic review of sorts on different examination findings, we see that the JVP, and hepatojugular reflux, correlates reasonably well with invasively measured CVP. The table of likelihood ratios below combines findings from the three studies addressing this question, including one where hilariously medical students were better at estimating CVP than staff physicians.