The causes of these conditions are variable and range from habits people have developed before they go to sleep to a number of medical problems that disrupt the normal sleep cycle.
Izimbangela zalezi zimo ziyahlukahluka, ku ukela emikhubeni abantu abathuthuki a ngaphambi kokulala kuya ezinkingeni eziningi zezokwelapha eziphazami a umjikelezo wokulala ojwayelekile.