I only sleep 4-5 hours a night. is this dangerous to continue long term?

Sleep: You may be genetically a short sleeper and if this is your pattern since childhood thats fine most studies show you need 6 to 8 hours of sleep to remain healthy usually, there are aways exceptions.

Average person: The average person needs 6 to 8 hours of sleep. Less than that can cause a decrease in performance and can make one more susceptible to getting sick. However there may be individuals that do fine on less sleep and others that need more. Your body will tell you what you need.

How much sleep?: First, here is a good general resource for some general information on this subject: http://www.Sleepfoundation.Org/article/how-sleep-works/how-much-sleep-do-we-really-need second- after reading that resource, consult with your own physician who can go into more detail based upon you and your specific life style, needs, and general health.