Is It Bad to Sleep With Wet Hair?

Medically reviewed by Sanja Jelic, MD

It's a widely held belief that going to bed with wet hair can be detrimental to your health, but there is a lack of strong scientific evidence to support this idea. While for most people, sleeping with wet hair is unlikely to cause serious health risks, there are some potential risks to consider.

This article will discuss the potential effects of sleeping with wet hair, including damage to the hair, creating an environment for microbial breeding, and the contribution to certain scalp conditions.

Is Sleeping With Wet Hair Bad for Your Health?

Sleeping with wet hair is unlikely to cause significant health problems for most people. Although it is commonly believed that going to bed with wet hair is detrimental to your health, there isn't enough credible, evidence-based scientific research to confirm the link between wet hair at bedtime and health problems for most people.

This doesn't mean there aren't valid reasons for ensuring you have dry hair before you tuck in for the night, such as protecting your hair from damage, keeping your pillowcase from becoming a breeding ground for microbes, or managing scalp conditions.

Protecting Your Wet Hair at Night

Wet hair has a weakened protein structure, which makes it more elastic and more likely to stretch and snap. This means wet hair tends to be more fragile than dry hair, making it more prone to breakage.

The friction from rubbing wet hair against the pillow can lead to damage over time, particularly if you move a lot in your sleep.

Many people prefer to shower or bathe at the end of the day, and fully drying hair may not be an option for time or convenience reasons. Sleeping with damp hair may also be used for some styling techniques. If you need to (or want to) go to bed with wet hair, there are steps you can take to help protect your hair from damage.

• Avoid soaking wet hair: Blot hair with a T-shirt or microfiber towel, let it partially air dry, or use a hair drying set to remove some of the moisture before sleeping.

• Reduce friction: Use a silk or satin pillowcase or wear a hair cap or scarf to bed to lessen the amount of friction.
  

• Condition your hair: Use conditioners or leave-in conditioners that help protect hair and reduce friction.

• Apply oil to your hair: Hair oils such as argan, commercial, or coconut oils may help protect against hair damage.
  

Never sleep with a hair dryer on, as this can create hazards such as burned skin or fire.

Pillowcases and Wet Hair

Pillows and pillowcases absorb water from wet hair, creating a damp sleep surface for your face. This can promote the growth of microbes such as bacteria.

A damp pillow or one that has collected residue from hair products could pose a problem for people prone to clogged pores or acne. While the link between sleeping with wet hair and acne is not established, some experts recommend sleeping with clean, dry hair tied or pulled away from the face.

Does Sleeping With Wet Hair Cause a Cold?

There is no scientific evidence that sleeping with wet hair causes a cold. The common cold is caused by viruses spread from person to person through droplets in the air from coughing or sneezing, or contaminated surfaces. Most adults experience a common cold infection about two to three times per year, whether or not they sleep with wet hair.

Hair Type and Going to Bed With Wet Hair

How likely your hair is to tangle, its tendency to frizz, and other factors related to hair type can affect whether (and how much) it may be damaged by sleeping with wet hair.

Hair strands are covered in a cuticle (a layer of brittle, scale-like cells) that contain various fatty acids. These fatty acids make the hair less likely to absorb water.

Chemically treating hair, and some hair styling products, can strip away these fatty acids, allowing the hair to absorb much more water, swell, and weaken its overall structure. This makes it more likely to break from friction on the pillow, become frizzy, and tangle as it dries.

Scalp and Hair Conditions to Consider

Our scalps, and by extension our pillowcases, naturally contain certain fungi and bacteria.

Under normal conditions, these microbes are kept in balance and don't cause problems.

Having a damp scalp for prolonged periods of time can make for an environment that promotes the growth of fungus or bacteria, which can cause overgrowth and lead to scalp problems, particularly in people with weakened immune systems.

For example, dandruff has been associated with an overgrowth of fungi such as Malassezia, and bacteria such as Cutibacterium and Staphylococcus.

Fungi and fungal infections that may cause scalp problems include:

• Malassezia: Found in hair follicles, it can lead to the skin condition seborrheic dermatitis, and its milder form dandruff, along with oily yellow patches on the face and head.

• Tinea Capitis: Also known as ringworm, Tinea Capitis is a fungal infection on the scalp that can cause itching, hair breakage, bald patches, and red, swollen, and flaky areas.

• Aspergillus Fumigatus: This type of fungus can be found on pillows and cause aspergillosis (an infection that can lead to serious respiratory disorders in certain people).

Summary

Despite the belief that sleeping with wet hair can cause health problems, there is little scientific evidence to support this idea. Sleeping with wet hair is unlikely to cause significant health problems for most people, but there are other reasons to reconsider going to bed with wet hair.

Sleeping with wet hair can damage the hair. Using measures such as conditioning and using a silk or satin pillowcase or hair cap may help prevent this if going to bed with damp hair is necessary.

Sleeping on a damp pillowcase may create a breeding ground for microbes such as bacteria, and may cause problems for those prone to clogged pores and acne.

Chemically treated hair may be more prone to damage if slept on while wet.

Sleeping with a damp scalp may promote the growth of bacteria and fungi, which can lead to infections and conditions such as tinea capitis and seborrheic dermatitis.

Read the original article on Verywell Health.