The Truths, Myths, and Evidence on Sleeping with Wet Hair

This has probably happened to you at least once: right after taking a bath at night, you go straight to your bedroom, ready to collapse from sheer exhaustion — only to be told that something bad will happen unless you dry your hair first. If stories about the side effects of sleeping with wet hair are keeping you up at night, it’s time you learned which are true and which are just wrong. After all, some of the most widely held beliefs actually have no evidence to support them.

To give you some peace of mind, let’s settle things once and for all. Can going to bed with wet hair…

Give you the sniffles?

Sleeping with Wet Hair Gives you Sniffles
Photo courtesy of Mojpe via Pixabay

This is a commonly-held notion all over the world. Whether you’re in Asia or Europe, someone will tell you that sleeping while your hair is wet can make you catch a cold or give you a headache. It sounds plausible; the reasoning goes that wet hair will make you cold, and being cold eventually leads to those horrible symptoms like having a runny nose and sneezing excessively.

As it turns out, this isn’t true at all. Colds are caused by viruses, not low temperatures. Unless you get exposed to a cold-causing viral agent (rhinoviruses are the most typical culprit), you’re not going to get the sniffles. And while cold weather can make people more likely to get a cold, it’s because of factors other than temperature; in rainy weather, it’s because of exposure to dirty water, and in the case of winter in other countries, it’s because of low humidity that dries out your nasal passage, making it easier for viruses to infect your body. So as long as your room is clean and germ-free, you shouldn’t catch a cold after sleeping with wet hair.

Give you a headache?

Sleeping with Wet Hair Gives you a Headache
Photo courtesy of RobinHiggins via Pixabay

Here’s another idea you might have heard. The theory goes like this: blood tends to go to the parts of your body that are cold. If your head is cold, your body will divert more warm blood to your cranial region, and the built-up pressure will eventually cause you to get a headache. Others suggest that the difference in temperature between your hair and your body can make your head hurt, though they don’t exactly explain the mechanism behind it (after all, don’t people actually put ice packs on their body to relieve aches and pains?).

This is another theory that sounds good but doesn’t hold water. There’s no empirical science to back this assertion. Based on anecdotal evidence, some people who sleep with wet hair wake up with headaches, and others don’t. It seems to be all down to different people’s stories, and not based on any proven medical mechanism. Unless you regularly experience headaches from sleeping with wet hair, there’s no reason for you to believe there’s an actual link.

Make your scalp itchy?

Sleeping with Wet Hair makes your Scalp Itchy
Photo courtesy of lannyboy89 via Pixabay

Some people might have told you that sleeping with damp hair will cause fungus to grow on your head, which can lead to dandruff and other scalp-irritating conditions. It’s because supposedly, the heat from your head, the moisture from your hair, and the lack of air circulation (because air is trapped between your head and your pillow) will encourage the growth of those agents, turning your scalp into a flaky, itchy petri dish quicker than you can say “head and shoulders.”

This is actually similar to the theory about getting a cold from wet hair: you can get an itchy scalp, but only if you’re actually exposed to fungal spores. That can only happen if your bed and pillow aren’t clean. So if you ask, “Is it okay to sleep with wet hair?”, the answer in this case is yes — as long as you practice good personal hygiene and replace your bedsheets and pillowcases regularly.

Make you go crazy?

Sleeping with Wet Hair Make you go Crazy
Photo courtesy of claudioscott via Pixabay

The supposed link between sleeping with wet hair and mental disorders is a fairly popular notion. But lucky for us, there’s no strong basis for it. We’re not saying that you should dismiss every piece of advice offered by your nanay and lola, but this is one piece of old-time wisdom that you should probably disregard.

There are a lot of conditions that scientists still can’t explain, but broadly speaking, they’ve determined several factors that can cause mental illness. These include genetics, brain injury, damage during pregnancy, misuse of certain drugs, exposure to toxins, and poor nutrition. There are some studies linking bacterial and yeast infections to mental illness, but such infectious agents have to enter your bloodstream first, which is highly unlikely to happen just through your wet hair and scalp. And even after those germs get into your circulatory system, they can’t affect your brain unless it gets through the blood-brain barrier. So if you’re not getting your full eight hours because you think sleeping with wet hair causes mental disorders, then you should stop worrying and start snoozing.

Make you look crazy?

Sleeping with Wet Hair Makes you look crazy
Photo courtesy of RyanMcGuire via Pixabay

The warnings that link disease, itchiness or craziness and sleeping with wet hair seem to be mostly based on incorrect beliefs or unproven stories. So in general, the answer to the question “Is sleeping with wet hair bad for you?” seems to be no, as long as you know what you’re doing. But that doesn’t mean it has no negative effects whatsoever. There’s one thing that will almost certainly happen — though it’s not so bad, compared to everything else we’ve discussed.

The truth is, sleeping without drying your hair can cause it to look unruly in the morning. If you don’t take the time to pat down and brush your wet hair before you go to bed, it’ll dry and set in a tangled mess. That’s even more likely to happen if you toss and turn in your sleep, which is why you might look like you’ve lost your mind after sleeping with wet hair. And brushing your knotted locks can cause breakage, especially if you’re in a rush and have no time to be careful about it. To avoid this, you can take a few minutes after bathing to pat your hair dry, or tie it in a loose braid. Using products like leave-on conditioners can also make things easier for you in the morning.

When sleeping with wet hair, some side effects are expected. But you can sleep well knowing the facts to help you deal with them effectively. Of course, if it makes you feel better, you can simply avoid bathing at night altogether. Whatever you choose to do, the important thing is for you to sleep comfortably and be fully rejuvenated when you wake up.