The Surprising Reasons To Avoid Sleeping With Wet Hair If You’re Dealing With Hair Loss & Breakage: ‘Leads To Scalp Dermatitis,’ Infections, And More

If you’re in the habit of going to bed with freshly washed, still-wet hair, you might want to rethink your nighttime routine—especially if you’re experiencing hair loss or breakage. Board-certified dermatologist Dr. Dray recently explained that while wet hair won’t give you a cold (a very old myth), it can create serious problems for both your scalp and your strands. Many of these issues don’t show up immediately, which is why people often underestimate just how damaging this habit can be.

Her first warning is that wet hair is significantly more fragile than dry hair. When you lie down with damp strands, the combination of moisture and friction from your pillowcase makes breakage, frizz, and overall fragility far more likely. This becomes even more problematic for anyone who is already dealing with thinning hair or shedding, as breakage can make hair appear even thinner. Dr. Dray notes that long hair is especially vulnerable since it can get trapped beneath your shoulders, back, or pillow as you sleep. Chemically treated, heat-styled, or bleached hair is at even higher risk of snapping overnight.

Sleeping with wet hair can also irritate the scalp more than most people realize. Prolonged moisture sitting on the skin increases transepidermal water loss and creates an environment that leads to itching, inflammation, and dermatitis flare-ups. For people with conditions like eczema or seborrheic dermatitis, this can worsen irritation and even indirectly impact hair growth. An inflamed scalp makes it harder for follicles to function normally, which is especially concerning for those with underlying thinning like androgenetic alopecia.

A third issue Dr. Dray highlights is the risk of a fungal infection called piedra, which forms tiny white or black nodules directly on the hair shaft. While it’s not extremely common, she explains that consistently sleeping with wet hair—particularly in tropical or humid climates—creates the perfect environment for this infection to thrive. Piedra weakens the hair shaft and increases fragility, making breakage more likely and treatment necessary.

Another surprising downside involves your bedding. Wet hair transfers moisture to pillowcases and sheets, creating a humid environment where dust mites thrive. For people with allergies, eczema, or asthma, this can lead to itchy and watery eyes, overnight congestion, increased eczema flares, and even dark, puffy under-eyes in the morning. Those who already struggle with sensitive skin or respiratory issues may find their symptoms worsening without realizing the cause.

Finally, Dr. Dray warns that regularly soaking your bedding with damp hair can encourage mildew growth. While mildew isn’t necessarily as directly harmful to your skin as dermatitis or fungal infections, sleeping on musty, moist sheets is far from ideal and creates an unhygienic environment that can irritate the skin over time.