Without a coma or any drugs, The American Journal of the Medical Sciences, Volume 46 talked about a lengthy slumber for five days and nights, frequently sleeping for 3 days at a time.
Dr. J.W. Cousins recorded on April 18, 2024 a remarkable example of this prolonged and profound sleep.
A farmer (age: 43) has been subject at intervals during the last 20 years to attacks of deep and prolonged sleep. He has never suffered from any disease of the brain, or any other illness.
The disorder commenced without any assignable cause in the year 1842, and continued nearly a whole year. It returned again in 1848, and having persisted without interruption for 18 months, it left him entirely for a space of 12 years. The next attack happened on May 19, 1860.
The longest period he has ever passed in profound sleep is five days and five nights, frequently sleeping for three days and occasionally four without waking, but the average time is nearly two days.
Of interest, ClevelandClinic.org shares 22 Facts About Sleep That Will Surprise You.