Insomnia is a sleep disorder. If you experience insomnia, you regularly have problems falling asleep, staying asleep, or you wake up several times during the night or wake up too early. Other symptoms of insomnia include feeling tired after you wake up, feeling irritable and tired during the day, or have trouble focusing or remembering.
- Mayo Clinic. Insomnia. https://www.mayoclinic.org/diseases-conditions/insomnia/symptoms-causes/syc-20355167 (accessed 5. August 2020)
- NHS UK. Insomnia. https://www.nhs.uk/conditions/insomnia/ (accessed 5. August 2020)