There has been a lot of research on the benefits of sleep for over all health. Interestingly, there is also some data which suggests that "oversleeping" is actually detrimental to health. For most people, the optimum number of hours to sleep is probably in the range of 6-7 hours per night, with sleeping more than that neither necessary nor beneficial.
Obviously there is a great deal of personal variation to this general rule. Therefore, if you are consistently sleeping 5 hours per night and waking up feeling refreshed, and if you are able to work productively throughout the day without feeling tired, then the amount of sleep your are getting is probably enough for your body.
On the other hand, if you do feel tired during the day, or finding yourself 'crashing' in the evening, then you should probably see your primary care doctor
about the problem. They can help you figure out if there is some factor or medical problem that is disturbing or limiting your sleep and, if so, help you figure out what to do about it.
As always, feel free to talk to your primary care doctor about this or any other general health issue at any time!