Because of fatigue or various other reasons, almost all of us have dozed off at a desk at least once. But usually, after only a short while, we suddenly “jerk awake.”

Why does that happen?

Before answering this question, we need to take a quick look at the sleep cycle.

A complete human sleep cycle consists of five stages, from the moment we fall asleep until we wake up. Depending on how long a person sleeps, this cycle will repeat several times.

The 5th Stage – REM Sleep

The fifth stage, called rapid eye movement (REM) sleep, accounts for about 25% of the sleep cycle (lasting around 70–90 minutes).

During this stage, signals from the brain are sent to the spinal cord, temporarily stopping skeletal muscle activity and reducing muscle tone.

According to Dr. Neil Kline, CEO of the American Sleep Association:
“Normally, the REM stage not only activates rapid eye movement but also causes skeletal muscles to temporarily stop functioning. These physiological changes help protect the body from injury during sleep.

However, in people with REM Sleep Behavior Disorder (RBD), the skeletal muscles continue to function as usual. This increases the risk of injury if they physically act out their dreams—since most dreams occur during the REM stage.”

Why We Jerk Awake When Napping at a Desk

When muscle tone decreases during sleep, it becomes difficult to keep the back and neck straight if you’re sitting upright. That’s why people who doze off often let their head fall to the side, struggle to fall into deep sleep, or suddenly jolt awake—because the body is not in a comfortable sleeping position.

How to Sleep More Comfortably When Dozing Off

So, how can you get a more comfortable rest when you nap on a plane, during a long bus ride, or even at your desk? Here are some suggestions:

1. Prepare “sleep gear” in advance

Have something to support your head—such as a pillow, a small blanket, or even a folded jacket. This will keep your neck in a more comfortable position.
Also, wear loose clothing and shoes if you want better-quality rest.

2. Block out noise and light

Wearing headphones at a moderate volume or using an eye mask is an effective way to reduce disturbing sounds and light.

3. Adopt the right posture

If you’re in a reclining chair, lean back about 40 degrees, and consider placing a pillow or folded blanket behind you to support your back.
If you’re resting your head on a desk, use a pillow or something soft to keep your head elevated. This prevents neck strain and avoids putting too much pressure on your spine by leaning forward.

Final Note

These methods are only temporary fixes for when you’re tired or traveling long distances. The real key is to get enough sleep, on schedule, and in a proper lying-down position—so you won’t find yourself nodding off and jolting awake all day.