Karolina Olsson (29 October 1861 – 5 April 1950), also known as "Soverskan på Oknö" ("The Sleeping Beauty of Oknö"), was a Swedish woman who purportedly remained in hibernation between 1876 and 1908 (32 years).This is believed to be the longest time that anyone has lived in this manner who then awoke without any residual symptoms.However, it has been claimed that Olsson may not really have been asleep and hibernating all that time.
There were many unexplained characteristics of her state; for example, her hair, fingernails, and toenails did not seem to grow.
Harald Fröderström observed in 1912 that she might have been pretending to sleep, or had been suffering from psychological problems and simply convinced herself that she was ill.