Don’t stay up late! Let’s learn about sleep deprivation

Feeling sleepy during the day is a sign of sleep deprivation


  • Pokémon Sleep is intended for entertainment purposes only and is not intended for use in detection, diagnosis, or treatment of any medical condition or disease.
  • The information provided in this article—and the sleep score registered through Pokémon Sleep—does not represent or substitute for a diagnosis from a physician or health care professional, and it cannot be used as a diagnostic or therapeutic treatment for a sleep disorder. Users should seek medical attention in case they present signs or symptoms that could be associated with sleep disorders.
  • Please note that the information in this article is intended for adults regarding sleep unless otherwise stated.

If you repeatedly find yourself getting sleepy during the day despite having slept soundly, it may be a sign that you’ve built up lots of sleep debt. At times like this, please try hard to get enough sleep. And if you still feel sleepy during the day, taking a 15- to 20-minute power nap may help. It’s been proven that these can reduce exhaustion, boost efficiency, and otherwise improve your performance. However, getting enough sleep at night is best. Don’t forget to focus on sleeping well at night, without staying up too late.

Reference material: Brooks, Amber, and Leon Lack. “A brief afternoon nap following nocturnal sleep restriction: which nap duration is most recuperative?.” Sleep 29.6 (2006): 831-840.

About Dr. Yanagisawa

Masashi Yanagisawa

Born in Tokyo in 1960, Masashi Yanagisawa completed his medical doctorate at a graduate school in the University of Tsukuba and is a member of the National Academy of Sciences. In 1987, he discovered the vasoconstricting peptide endothelin while in graduate school, and in 1988 he discovered orexin, a neuropeptide that regulates sleep and wakefulness. At 31 years of age, Professor Yanagisawa came to the United States, where he presided over laboratories at the University of Texas and at the Howard Hughes Medical Institute over the span of 24 years. He founded the International Institute for Integrative Sleep Medicine (WPI-IIIS) in 2012, establishing it under the Japanese Ministry of Education, Culture, Sports, Science and Technology’s World Premier International Research Initiative. Professor Yanagisawa founded S’UIMIN Inc. in 2017 and currently acts as CEO.

He supervised the provision of sleep-related information during the development of Pokémon Sleep.

He was awarded a Japanese Medal with Purple Ribbon in 2016, received the Asahi Prize and the Keio Medical Science Prize in 2018, was named a Person of Cultural Merit in 2019, and received the Breakthrough Prize in 2023.