My friend says it is not healthy to sleep only 5 hrs per night. I am 68, on no routine medications, no BP or heart problems, exercise 2-3 x wk and am very active. I stay awake till about 12 midnight, read for an hour, then sleep until around 6. If weather is hot I may take an afternoon nap 1/2-1 hr. I m active in volunteer work and still work parttime (retired biologist) Should I be concerned about not sleeping 8-9 hrs per night. This sleep pattern has been going on for 30+ years.