Why is it cold that my hands and feet itch?

In winter, the weather gets cold and the air becomes dry. At this time, many people's skin will itch, especially when they just take off their clothes before going to bed at night, and they itch badly from arm to leg. What the hell is going on here? It turns out that the climate in autumn and winter is cold, and sebaceous gland secretions are difficult to discharge to the body surface. Scientific tests show that the melting point of fat secreted by human sebaceous glands is about 30 degrees Celsius. In the cold season, skin fat is almost solidified into a solid state, which is more difficult to discharge, which makes people's skin dry more obviously in winter. Especially for the elderly, with the increase of age, the metabolic function gradually declines. Because of the decrease of endocrine and the disorder of sebaceous gland secretion, the skin will be dry and itchy. Moreover, the activity function of skin sweat glands is obviously lower than that of young adults, and the amount of perspiration is reduced, which makes the skin surface lack of moisture, which is of course drier and more itchy in dry winter. Tracing back to the source, itching is an abnormal feeling caused by chemicals, bacteria, parasites, abnormal metabolites from inside and outside the body, skin inflammation, chemical fiber fabrics and other factors stimulating nerve receptors on the skin. Moreover, both itching and pain are produced by the same peripheral nerve receptor located in the dermal papilla, just because the severity of stimulation is different, ranging from itching to pain. Don't scratch your hands too much when your skin itches, especially when it itches. In fact, it enhances the stimulation to the skin and causes pain to the skin, thus covering up the itchy feeling. With the passage of time, the skin surface will undergo proliferative changes. Roughness and hypertrophy of skin itself is the stimulation of peripheral nerve receptors, which will aggravate itching and form new conditioned reflex. The result is that the more you scratch, the more you itch, causing a vicious circle. Some people will have a hot bath and a nice perm to relieve itching. However, the end result is often that the hotter the itch. This is because taking a hot bath, due to frequent burns and soaping, will make people's epidermis lose the already insufficient fat film, and even the normal moisture content of the skin surface is difficult to maintain, so it will be more itchy. It seems that this way of relieving itching is not enough. You should do this. It itches. First of all, you should pay attention to strengthening your physique and exercising properly. Massage the whole body before and after undressing in the morning and evening to promote skin microcirculation and reduce skin dryness. Secondly, good living habits such as maintaining personal hygiene, changing underwear frequently (underwear is preferably soft cotton and silk) and eating less irritating food can effectively prevent itching. Use warm water bath instead of hot water bath, 1 ~ 2 times a week, and avoid using strong alkaline laundry soap, use neutral soap or bath liquid, and the dosage should be appropriate, and do not rub for a long time. Teach you three ways to stop itching. When local skin itches, fresh towel gourd leaves can be pounded and applied to the affected area, and the treatment effect is better. When the skin is itchy, you can put a pinch of cigarette ash into a container, drop a few drops of water to make it paste, and apply it to the affected area to stop itching.