Now there are many office workers. Due to the working hours, many female friends like to wash their hair at night. They often fall asleep before their hair is dry. So what's the harm of girls washing their hair at night? People with strong body resistance have normal thermoregulation function. Through regulation, the two processes of heat production and heat dissipation are balanced, that is, when the body temperature tends to decline, the heat production increases and the heat dissipation decreases, so that the body temperature is still maintained at 37 ℃.
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The harm of girls washing their hair at night
1. Girls are easy to catch cold when they wash their hair at night
People with strong body resistance have normal thermoregulation function. Through regulation, the two processes of heat production and heat dissipation are balanced, that is, when the body temperature tends to decline, the heat production increases and the heat dissipation decreases, so that the body temperature is still maintained at about 37 ℃.
But for people with weak body resistance, their ability to automatically regulate body temperature and maintain normal body temperature is poor, so when the whole body or a part of the body is cold, it is easy to catch a cold.
After we wash our hair with hot water, the capillaries on the scalp will expand due to the warming effect, and the body will radiate more heat to the surrounding area. At the same time, because the hair is wet after washing, a lot of water will evaporate out, and a lot of heat will be taken away. Generally, 500 calories are taken away when one gram of water evaporates.
Because of the increase of heat dissipation, the body will be frozen, so the capillary of upper respiratory tract will be contracted reflexively, the local blood flow will be reduced, and the resistance of upper respiratory tract will be reduced, so that the virus or bacteria that already exist in the local area will take advantage of the deficiency, grow and reproduce, and cause upper respiratory tract infection, thus leading to cold symptoms, such as runny nose, stuffy nose, headache and even fever.
If you fall asleep when your hair is not dry, the regulating function of the thermoregulatory center is low, and you are more likely to catch a cold.
2. Girls tend to have a headache when they wash their hair at night
People sleep with wet hair at night. Wet hair, open air conditioning sleep, the human body in a relaxed state, slow metabolism, easy to fatigue, resistance will decline, it is easy to get cold, wake up the next day, often feel headache, fatigue. Even lead to headache, abdominal pain, diarrhea, dyspepsia and joint discomfort.
Washing your hair before going to bed makes the water stay on the scalp, which is covered with many capillaries. If the hair is half wet and half dry, cold and wet invades, and the blood vessels contract, causing local ischemia and spasm, it will cause headache. For a long time, it will lead to qi stagnation, blood stasis and meridian obstruction.
And after washing your head, you sleep in the air-conditioned bedroom. If you blow your head into the cold air, you will get cold and wet, leading to disease. Many people sleep until midnight will appear scalp numbness, and accompanied by pain. In the long run, it will lead to a kind of chronic diseases such as phlebitis under the scalp.
3. Girls wash their hair at night easily lead to scalp diseases
Wet hair sleep easily cause dizziness, nausea. People who have the habit of washing their hair before going to bed at night are most likely to get sick if they don't dry their hair seriously and leave a lot of water on the scalp surface, especially when the temperature is low at night in winter. Sleep in the middle of the night will feel local scalp numbness, accompanied by continuous pain. The next morning, there will be inexplicable headache or dizziness, and nausea in severe cases. In the long run, it will also lead to a disease called 'sub scalp phlebitis'.
When is not suitable for girls to wash their hair
1. Menstrual period
Due to the special physiological changes during menstruation, the body is relatively in a state of deficiency of Qi and blood, and its resistance decreases. According to traditional Chinese medicine, the head is the meeting of all Yang, the blood supply to the brain is relatively insufficient during menstruation, and the head is also vulnerable to wind cold. The cold and hot stimulation of shampoo may also cause headache, dizziness and other manifestations of cerebral insufficiency and vasospasm, which is called "Toufeng". Therefore, should try to avoid shampoo during menstruation.
2. After dinner
Full meal, bath, skin and muscle blood flow increase, stomach does not have enough blood, will affect the digestion and absorption of food. Although bathing is not strenuous exercise, but for people with cardiovascular and cerebrovascular diseases, washing your hair and bathing immediately after meals may cause cardiac ischemia and trigger the sudden onset of cardiovascular and cerebrovascular diseases.
So it's best to take a bath after a meal for an hour or two. You can choose the bath time according to your constitution. For example, people with weak constitution can choose to take a bath at noon when the Yang is the strongest.
3. After drinking
Many people like to drink two cups. If they wash their hair soon after drinking, they are likely to have dizziness, black eyes and vomiting. People with cardiovascular and cerebrovascular diseases, usually do not use too cold water to wash their hair, drink more attention. Some people like to go out for a walk after drinking. If there is a cold wind at this time, the evil of wind and cold will take advantage of it.
What should girls pay attention to when they wash their hair
1. It's best to wash your head three to four times a week.
2. People and mental workers who work outdoors for a long time can appropriately increase the frequency of shampoo. In addition, they should also comb regularly to promote blood circulation.
3. People who have the habit of washing their hair at night should try their best to change the habit of washing their hair at night. Secondly, they should dry their hair after washing or blow dry it with an electric hair dryer to ensure that they are clean, relaxed and healthy.
4. Washing your hair every day not only can't protect your hair, but also can cause damage to your hair. Because washing your hair too often will completely wash off the oil secreted by sebaceous glands, so that the scalp and hair lose their natural protective film, but it is not good for the health of the hair.
5. For people with greasy hair, when choosing shampoo, try to use cheaper shampoo. Cheap shampoo is better for greasy hair, which is beneficial to the cycle of hair.