@ak
What Kevin says about height can be important for some people(eg with bad back or other limitations) .. but I think one of the more important aspects of tripod height is more about how low it can be set too, rather than matching it to your own height
Arthur, if the tripod is not high enough so that you can use it without stooping, and without it being extended as stability suffers, if you don't already have a crook back you are well on the way to getting one.