Sleep structure (architecture)
People normally sleep in cycles during the night that involve 2 states of sleep:
- rapid eye movement or REM sleep
- non-rapid eye movement or NREM sleep
There are 4 stages of sleep: 3 stages in NREM sleep (Stages 1 to 3) and 1 stage in REM sleep (Stage 4). We dream during REM sleep. The NREM stages are:
- Stage 1 (transition stage)
- Stage 2 (light sleep)
- Stage 3 (deep sleep, slow wave sleep)
Research has shown that people with migraines have less total REM sleep than people without migraines.
During an evening, people move through the sleep cycles about 4 to 6 times. The states and stages of sleep are collectively called
sleep architecture.
Learn more about what happens to your body in each
state and stage of sleep.
Why do people dream?
It’s thought that dreams clear out old information from the brain, build and organize memory, and help with learning and problem solving.
Sleep control
Sleep is controlled by the body in 2 ways:
Sleep pressure is the body's strong push towards sleep. It steadily builds throughout the day. Sleep pressure is strongest at night and makes it hard to stay awake.
Adenosine is a substance in the body that helps with sleep pressure by binding to special receptors. Unfortunately, caffeine can bind to these receptors and prevent adenosine from working like it’s supposed to. When this happens, it may take longer to fall asleep and there may be less deep sleep.
Napping (especially after 3 p.m.) can also push back sleep pressure.
Could the way you manage your headaches make your sleep problems worse?
Headache researchers Ong and Park found that some common short-term ways to cope with headaches, like taking naps to sleep off a headache or using caffeine during the day, could lead to long-term sleep problems and possibly worsen headaches over time.
They suggest using other headache management strategies, as well as regular sleep hygiene and stress management techniques. These are covered later in the module.
Circadian rhythms help control sleeping and waking. The brain’s “biological clock” drives these special rhythms. There are also special molecules in the body’s cells and tissues that support these rhythms.
The clock receives lots of input, but information about light has the greatest impact. The clock has nerves that connect to the eyes and, through connections in the brain and spinal cord, to a gland in the brain that secretes melatonin. Melatonin is a hormone that is released when the eyes detect that the environment is dim or dark. The highest amount of melatonin is released around midnight. Regular routines for sleep, meals, work, and other activities can help support circadian rhythms.
Shiftwork can disturb a person’s circadian rhythms. Research on shiftwork and migraines is mixed: some researchers report that shiftwork doesn’t impact headaches, while others report that it does.
- One study showed that migraines became more frequent during shiftwork and less frequent with a return to daytime work. These authors suggested a work accommodation to permanent day shifts.
- Another study showed that later sleep times and misalignment of circadian rhythms significantly increased the number of migraine days in women with chronic migraine.
- A group of authors reviewed several shiftwork-migraine studies and concluded there were links (not causes) between shiftwork and headaches, including significantly higher rates of migraine in shift workers and a 44% risk of night shift workers developing headaches.
For information about coping with shiftwork, see Sleep Hygiene: Troubleshooting.
Behaviours like these might affect circadian rhythms. Do any of these apply to you?
- keeping the bedroom light on when you go to sleep
- watching a movie on your laptop just before bed
- working a night shift when you usually work in the daytime
