Why Do People Wake Up at 3 a.m.?

Waking up in the middle of the night is a common behavior that occurs for many reasons, ranging from bad dreams to simply needing to use the restroom. In many cases, people can easily fall back asleep if they happen to wake up suddenly during periods of deep sleep. However, waking up at or around 3 a.m. when the body and brain move into a lighter sleeping phase may actually make it more difficult to go back to sleep. 

Why Do I Keep Waking Up at 3 a.m.?

Waking up at or around 3 a.m. is also referred to as nocturnal awakening, and it's usually related to the body's sleep cycle. While an individual's specific waking times can vary depending on what time they initially go to sleep, nocturnal awakening at 3 a.m. is believed to occur when the body and brain shift from deep sleep into REM sleep. REM sleep, also referred to as light sleep, occurs in several stages throughout an individual's sleep cycle. One study in the United States concluded that up to 35.5% of people surveyed experienced nocturnal awakening three or more nights of the week. 

The first stage of REM sleep typically happens as a person drifts off to sleep after retiring to bed for the evening. During this stage, the brain slows down and the sleeper becomes drowsy and relaxed, but they may still be aware of their surroundings. The second stage of REM sleep happens immediately after the first stage, and during this time the body and brain wind down to prepare for deep sleep.

The next sleep stage is the deep sleep stage. When an individual reaches the deep sleep stage, brainwaves are very slow and the body transitions into a state of repair. The body and brain are completely relaxed, and the individual may not wake up as easily as they would during an REM stage. The third REM stage (or final sleep stage) makes up the last portion of an individual's sleep cycle. In many people, this final stage occurs around 3 a.m. or early morning hours. If a person falls asleep around 10 p.m. or 11 p.m., by 3 a.m. they're most likely experiencing the final stages of REM sleep in which the brain is more active and sleep patterns are significantly lighter, making it easier to wake up and have difficulty going back to sleep. 

Can Waking Up at 3 a.m. Indicate a Health Problem?

While waking up at 3 a.m. is often linked to an individual's natural sleep patterns, continual sleep disturbances may indicate an underlying health condition or emotional distress. Symptoms from common conditions such as heartburn or acid reflux may become exacerbated when an individual lays down, causing them to wake up in the middle of the night. Individuals diagnosed with heart failure may also struggle with sleeping through the night, as the condition can cause fluid to build up in the lungs, leading to shortness of breath when lying down.

Studies have also shown that nutritional deficiencies and diets low in vitamins A, C, D, E and K may contribute to poor sleep patterns, and high-carbohydrate intake can affect the body's deep sleep and REM cycles. Sleep apnea is a medical condition in which breathing becomes interrupted during sleep intervals. When the brain receives the message that the body has stopped breathing, the sleeper usually automatically wakes up and normal breathing is restored. In some cases, people with sleep apnea use continuous positive airway pressure (CPAP) machines at night to help regulate their breathing as they sleep. 

Stress, anxiety, depression and other mental health conditions may also cause nocturnal awakening. When a person is under stress, their thoughts may race as they turn in for the night, which can lead to restless, interrupted sleep. People who struggle with anxiety may find themselves waking up suddenly following a jarring dream or nightmare. Individuals with depression sometimes have trouble falling asleep, which can also disrupt sleep patterns. 

Is Nocturnal Awakening Preventable?

While certain instances of nocturnal awakening due to health conditions or an individual's natural sleep cycle may not be preventable, there are steps you can take before turning in for the night that may promote uninterrupted sleep. Limiting caffeine intake for several hours before bedtime can help encourage relaxation as the day comes to an end and may prevent nocturnal awakening. Taking a warm shower or bath or performing gentle stretching exercises before bed are good ways to relax before bed, which may help reduce episodes of nocturnal awakening caused by stress or anxiety. In cases where sleep disruptions affect an individual's health or ability to function, physicians sometimes recommend treatment with prescription sleep-aid medications.