Why do you put your arm under pillow when sleep?

There are a few reasons why people might put their arm under their pillow when they sleep.

* Comfort. Some people find that putting their arm under their pillow helps to support their head and neck and makes them feel more comfortable. This can be especially helpful for people who suffer from neck pain or stiffness.

* Warmth. Putting your arm under your pillow can help to keep your arm warm. This can be especially beneficial for people who live in cold climates or who have poor circulation.

* Security. Some people find that putting their arm under their pillow helps them to feel more secure and protected. This can be especially helpful for people who are anxious or who have experienced trauma.

* Habit. Some people simply put their arm under their pillow because it's a habit they've developed over time. There may not be any specific reason why they do it, but it's something they've always done and it feels comfortable.

Ultimately, there is no right or wrong way to sleep. If you find that putting your arm under your pillow helps you to sleep more comfortably, then there's no reason to stop.