Tremor can increase the heat energy generated by the body from 40 to 60 kilocalories per hour to 300 kilocalories, cause the blood vessels on the body surface to contract, and reduce the heat loss of the body to keep warm.
In addition, when it is cold, most people stay indoors, and the sun exposure and exercise are reduced; In winter, the platelet and coagulation function in blood are stronger than in summer. In addition, it is easy to cause respiratory tract infection in winter, increasing blood viscosity and coagulation function, which will lead to poor blood circulation and aggravate the symptoms of cold hands and feet.
Second, the clinical characterization
Even healthy people, their hands and feet may turn purple with cold in cold weather. Sympathetic nerve excitation causes arterial blood vessels to contract, microvessels and venous blood vessels to expand relatively, and blood oxygen content in tissues decreases. Therefore, the skin is blue-purple, extending from the fingertips to the palm of your hand, which will last for a period of time, and the light pressure will not turn white, which mostly occurs in women under 30 years old.
Sometimes there will be a "reticular green spot" change, and some skin will appear mottled red and blue reticular fine lines, which may be produced by women or men in their thirties. Most of these skin changes are harmless and can be improved by keeping warm, but sometimes they also occur in the skin with acute arterial embolism.
There is also a skin change called "Raynaud's syndrome", which occurs in women aged 20 to 40. There are periodic color changes on their fingers or toes, from white to purple and then to red. Most of them occur in fingers, with only one or two fingers (toes) at first, and then gradually spread to other fingers (toes). A few even reach the earlobe and the tip of the nose, and most of them are fine, as long as they keep warm and avoid exposure to cold environment. About 15% will get better with time, but 30% will get worse gradually. Less than 10% fingers will become hard due to repeated hypoxia, and less than 1% fingers will be amputated due to severe ischemia.
3. When should I see a doctor to check my cold hands and feet and the skin color change caused by cold? As long as there is no pain, normal pulse, no wound on the skin, and normal skin color or oral mucosa color in other parts of the body, most of them are not serious.
Arterial diseases caused by arterial spasm or other diseases often change the skin of the affected area with hypoxia: pale, smooth and bright skin, sparse hair and thick nails; In severe cases, the skin is purple-black, painful, ulcerated, gangrenous and even amputated.
Therefore, patients with Raynaud's syndrome with cold hands and feet combined with abnormal pain, numbness, weak or disappearing pulse, the above skin lesions, and frequent or aggravated attacks should seek medical examination.
If other major medical diseases are known, such as hypertension, heart disease, diabetes, autoimmune diseases, arterial diseases, etc. You should see a doctor as soon as possible. In addition, it should be noted that many drugs can also cause arterial vasoconstriction, such as many sympathetic drugs and many commonly used sedatives and hypnotics, which will affect sympathetic nerve activity and vasoconstriction, and should also be confirmed or adjusted by doctors.
Fourth, the way of preventive health care.
(1) Keep warm: Besides wearing warm clothes, remember to wear hats, scarves, gloves and breathable soft and warm shoes. It is important to keep the head, face, neck and hands warm, because the head and neck heat dissipation accounts for 30% of the whole body heat dissipation. It is best to have temperature control equipment indoors, but pay attention to the safety of electricity use.
(2) More sunshine and more exercise: In addition to keeping out the cold, it can also reduce blood viscosity and promote blood circulation. Outdoor activities must pay attention to keep warm, and try to choose a time with higher temperature and better air.
(3) Avoid wearing too tight socks and underwear, so as not to affect the arterial blood flow of limbs.
(4) Moderately supplement calories to avoid hypothermia caused by hunger or hypoglycemia. Eat less oil and sweets, eat more fruits and vegetables to supplement vitamin C, and improve blood viscosity.
(5) Avoid excessive drinking: Although a small amount of drinking will dilate blood vessels in the skin, alcohol will inhibit the central nervous system, thus inhibiting the "trembling" thermogenic reaction and inhibiting the production of sugar in the liver, leading to hypoglycemia. Skin vasodilation can also lead to more body heat loss, resulting in the risk of hypothermia.
(6) Be sure to quit smoking, including secondhand smoke. Smoking can cause sympathetic nerve excitement and aggravate vasoconstriction or spasm.
(seven) generally cold hands and feet, pay attention to keep warm, rarely need medication. But serious cases, especially those with obvious skin lesions, should be examined in detail to find out the reasons and prescribe the right medicine.
(8) Keep the skin clean, and use moisturizing cream appropriately to avoid chapping and trauma, especially those with skin lesions.
(9) Patients with major medical diseases should take medicine regularly according to the doctor's advice to stabilize the disease control. Patients who use aspirin antiplatelet or anticoagulant drugs must not stop taking them at will. Long-term drug users should discuss drug use with doctors if their hands and feet are getting colder in winter.
(10) Avoid going in and out of places with crowded people and poor ventilation, avoid contact with patients with respiratory infections, and also get flu vaccine.
You should have a cold constitution. Keep warm when sleeping at night. Drink a glass of warm milk and soak your feet with hot water before going to bed, which will last longer than 15 minutes. Keep it, remember.