Irregular sleep patterns refer to an inconsistent or unpredictable schedule when it comes to going to bed and waking up. This can mean that a person may have trouble falling asleep at night, or they may wake up frequently throughout the night and have difficulty getting back to sleep. It can also indicate that someone's sleep patterns vary greatly from day to day, with some days being longer or shorter than others. Irregular sleep patterns are often associated with stress, anxiety, and other mental health issues, as well as disruptions in the body's internal clock (circadian rhythm).