Can you sleep in ordinary clothes and what speaks against it

Short answer: You can, but daytime clothes are made for standing and walking. Seams, zips and stiff edges sit wrong when you are lying down for eight hours, and the clothes have been out with you all day.

It is not forbidden

Plenty of people sleep in an old T-shirt or joggers, and there is nothing wrong with that. It is not harmful, and for some it works fine. But there are a few reasons nightwear is made differently from daywear, and they are mostly about comfort and how often your bedding needs washing.

The seams are the difference

Nightwear has flat seams precisely because you lie on them. An ordinary T-shirt often has a seam down the side that presses when you sleep on your side. Labels at the neck and side can scratch too. Small things by day, but at night you lie on them for hours. See men's sleep T-shirts.

Cut for lying down

Nightwear is cut longer and looser so it does not ride up when you turn over. Daywear is cut for an upright body, where gravity keeps it in place. Lying down, a short T-shirt pulls up over your stomach, and tight trousers pull across the knees when you bend your legs.

Zips, buttons and pockets

Jeans and work trousers have zips, buttons and rivets that press when you lie on them. Pockets with things in them, or just a thick fabric edge, become lumps under your hip. These are the things that make the biggest difference. Nightwear usually has none of them, or they sit where you do not lie.

The material

Daywear is often made to hold its shape and stand up to wear, so the fabric tends to be stiffer. At night you need a fabric that is soft and can move moisture away from the skin. A stiff fabric that holds moisture turns clammy during the night and can make it harder to sleep through.

Hygiene

Daytime clothes have been out all day, on the bus, at the office and on the sofa. If you sleep in them, all of that comes into bed. It means the bedding needs washing more often and gets dirty faster. A clean set of nightwear used only in bed keeps everything fresher. See bamboo bedding.

A signal to the body

Many people find that changing into nightwear becomes part of a fixed evening routine. It is a small switch that marks the end of the day. It does not suit everyone, but for some it makes it easier to wind down once the day's clothes are put away.

The exception

Soft lounge trousers without pockets or hard seams are fine to sleep in. So is a soft T-shirt without stiff edges. What matters is not what the clothing is called but how it is made. Pick pieces designed for relaxing. See men's bamboo loungewear.

An easy place to start

If you want to try nightwear without buying a full set, start with a single top. A soft T-shirt with flat seams for night is an easy first step, and you will quickly feel the difference. Pair it with soft trousers you already own and see how it feels.