If you don't dry your hair because you're lazy... you might get bitten by that 'bug' on your scalp.

 

Hair can be easily damaged.

First, wet hair is more easily damaged than dry hair. Hair is composed of an inner cortex and an outer cuticle. When water is absorbed into the inner cortex, the hair swells and becomes more susceptible to damage from external stimuli. It tends to stretch more, split, and break. The longer the hair remains wet, the more water is absorbed into the inner layers. As a result, it becomes more vulnerable to external stimuli, and the ends of the hair are more likely to split.

Sleeping without drying your hair increases the risk of scalp inflammation and hair loss. A damp scalp provides an ideal environment for bacteria to thrive. Additionally, dust and other impurities easily stick to it, clogging pores and potentially causing scalp inflammation. When the scalp becomes inflamed, even daily hair washing may not prevent it from becoming greasy, producing excess dandruff, and causing itching. In severe cases, it can lead to hair loss. Hair grows in cycles, but if scalp health is poor, hair cannot grow healthily, resulting in thinning hair and hair falling out during growth.

If you don't dry your hair thoroughly before sleeping, lice can infest your scalp. Wet hair and scalp left on the pillow late at night create an ideal environment for lice. Lice do not transmit diseases to humans, but they are classified as pests because they gnaw on clothing, books, and other items. They prefer dark, humid, and warm places, and their favorite food sources are human skin flakes and dandruff. If there are no lice in your home, that's fine, but if they are already present, they may gather around your head when you sleep with damp hair. Nighttime, darkness, the heat and moisture of the scalp, and an abundance of dandruff and skin flakes make it an ideal environment for lice. Especially during the humid and hot summer monsoon season, lice outbreaks become more frequent. To eliminate lice, the most important step is to reduce indoor humidity. Placing charcoal or moisture absorbers in closets and other areas where lice mainly reside can help lower humidity.

To prevent inflammation, hair loss, and insect bites, it is important to completely dry your hair after washing and before sleeping. After washing your hair, press the hair with a towel to remove excess water, then use a hairdryer to thoroughly dry the scalp and hair roots. It is better to use cool air when drying. Hot air can promote sweat and sebum secretion from the hair roots, which can negatively affect scalp and hair health. If you need to comb your hair, avoid doing so when it is wet; wait until it is completely dry and then gently comb to reduce hair damage.