There are many factors, both internal and external, that can influence the quantity and quality of the sleep we obtain.

Several factors—many of which you can control—affect the quality of sleep you get each night.

  • Pain, anxiety, and other medical conditions such as chronic stress can keep you up at night, worrying over problems, deadlines, and frustrations
  • Your biological clock
  • Sleep environment including light, noise, and temperature
  • What food you eat, including products containing caffeine or alcohol, can disrupt sleeping patterns
  • Chronic medical conditions

References:

http://healthysleep.med.harvard.edu/healthy/science/how/external-factors

https://www.takingcharge.csh.umn.edu/enhance-your-wellbeing/health/sleep/what-affects-sleep

http://healthysleep.med.harvard.edu/healthy/getting/bio-clock