2. When people are sleeping, the blood supply to the head is slow and the resistance is weak. Wet hair will take away the heat from the head, which will form a health hazard in the long run. Therefore, it is best to wash your hair when the temperature is stable during the day, or wash your hair after a short rest at home from work. In this way, there is enough time for the hair to dry naturally, thus avoiding some diseases. ?
3. Sebaceous glands on the scalp and hair follicles on the hair secrete oil every day, which protects and lubricates the scalp and hair. If you wash it too often, this layer of oil will be completely washed away, making the scalp and hair lose their natural protective film and become dry and easy to split. Actually, there is no need to wash your hair every day. The specific situation varies from person to person. Under normal circumstances, it is advisable to wash it 2-3 times a week; If you are often outdoors, the frequency can be increased appropriately; And rarely go out, people with oily hair can wash it once a week.
4. The water temperature of shampoo must be appropriate. Overheated water will relax the blood vessels on the scalp surface, while supercooled water will stimulate blood vessels to contract. Excessive relaxation or contraction of blood vessels can cause discomfort. For friends with basic cerebrovascular diseases, it may cause dizziness and headache. ?
In addition, after washing your hair, you must blow dry it thoroughly before going out or going to bed. When the hair is wet, the evaporation of water will take away the heat from the head, making it easy to catch cold and uncomfortable, causing health hazards. Note that after washing, you can apply some conditioner, rinse it, dry it thoroughly or blow dry it with hot air.
Extended data
One bogey: scratch your scalp with your nails when washing your hair.
There are many bacteria in nails, and once the delicate scalp is scratched, it is easy to induce infection. When applying shampoo, gently push the scalp with your fingertips to decontaminate and promote blood circulation.
Two bogeys: conditioner is applied to hair roots.
Because the hair follicle is open when washing hair, the conditioner is coated on the hair root, and the chemicals inside can easily penetrate and block the hair follicle. It is recommended to straighten your hair first and apply it to the hair tip near your ears. Be sure not to let the conditioner touch your scalp.
Three bogeys: sleeping with wet hair
When the hair is wet, the hair scales open, and the hair is delicate and not resistant to friction. If you sleep in a semi-wet and semi-dry state, it will cause the cuticle to become thinner and make your hair dry.
Four bogeys: wash your hair directly without combing your hair.
"The skin doesn't exist, but the hair is connected." Scalp is very important for hair. Comb your hair with a wet comb before washing your hair, so that dirt and dust attached to your scalp float on the surface, so that you can wash your scalp and hair at the same time. In order to avoid hurting the scalp, it is recommended to use a comb with wide teeth and round head.
Five bogeys: Go out immediately after washing your hair.
Studies have found that hair receives more than twice as much ultraviolet radiation as face. Ultraviolet rays will make hair scales thin and fall off. Go out immediately after washing your hair. Ultraviolet rays can easily cause hair to break and split. If you go out, you'd better take an umbrella or wear a hat to prevent ultraviolet rays.
Baidu Encyclopedia: Precautions for Shampooing