Specifically, fibromyalgia patients tend to have reduced REM sleep and increased non-REM sleep. During REM sleep, the eyes move rapidly and dreaming takes place. When people are awakened during non-REM sleep, they report that they were thinking about everyday matters but rarely report dreams. As sleep progresses, there is a deepening of sleep from Stage 1 to Stage 4, with progressively slower brain-wave activity until REM sleep, when suddenly the brain becomes much more active. In adults, the first REM sleep cycle is usually triggered ninety minutes after going to sleep and lasts about five to ten minutes.
Most adults experience five or six sleep cycles each night.
The sleep defects in fibromyalgia go well beyond reduced REM sleep and increased non-REM sleep. As a result, people with fibromyalgia wake up feeling tired, worn out, and in pain. Conversely, when they sleep poorly, their symptoms are more severe.