Cold hands and feet that don't warm up, even under a heavy quilt, plague many people and rob them of sleep, especially in autumn and winter.
This is especially true for women. Their core body temperature is slightly higher than that of men but they have cold extremities more often than men, who have more muscle and fat to keep them warm.
So there really is something to the saying, "Cold hands, warm heart."
It's all about poor circulation in the extremities and it happens to everyone once in a while. If it's persistent, a doctor should be consulted.
It's caused by poor blood circulation, which in turn can be caused by a heart condition, ailments, exposure to the cold, too much smoking and other things.
Traditional Chinese medicine says that for both men and women cold extremities are called by disconnection between yin and yang energy, and this is often caused by insufficient yang energy inside.
Aerobic exercise, foot soaks, and yang-reinforcing foods can help relieve the problem.
It is said that one in four women suffer from cold extremities in autumn and winter, especially at night.
Extremities (and the rest of the body) get cold when warm blood does not circulate properly after leaving the heart. Blood vessels contract in cold weather, contributing to the problem.
Heat is lost more quickly in hands, toes, knees and shoulders - areas with less fat and blood vessels.
Slim people, especially women, lose heat more quickly as they have less fat and muscle to keep them warm. Stress, fatigue and endocrine disorders contribute to cold feet. A woman's body temperature rises slightly during ovulation.
TCM classifies cold limbs as a jue ailment that happens when yin and yang energies cannot connect in the body, according to Dr Hu Weiqin writes in his popular book "Jiang Zhongyi Jinxing Daodi" ("Cherish TCM Forever") published in 2008. He used to be the physician to senior Chinese leaders, such as Marshal Zhu De.
TCM holds that yang conveys energy to the limbs, while yin conveys energy to the organs. The yin and yang energy connects with each other in a circle inside the human body. If the two energies can't link up, jue and cold limbs happen.
Jue may result from various energy imbalances. Han jue (cold jue) accompanied by deficient yang energy and blood and pathogenic cold is the most common cause. In this case the deficient yang energy is too weak to reach the limbs.
Accumulated pathogenic heat or dampness can also cause energy disconnect, as they can block yang energy at the organs and prevent yang energy traveling to the limbs. These often feel their core is warm, though their limbs are cold. They may suffer from pathogenic heat-related problems such as constipation and thirst, according to Dr Hu.
These patients may need special diagnosis and prescriptions, while "warm reinforcement" is recommended for people with deficient energy and blood.
Regular aerobic exercise promotes blood circulation and metabolism and relieves cold limbs. Jogging, tai chi and rope skipping are among many good exercises, including a treadmill. Heavy exertion should be avoided since heavy sweating results in "leaking" of yang energy and aggravates the problem of chilled extremities.
Warm foot soaks accelerate blood circulation. Soak feet and calves at 40 degrees Celsius for 20 minutes before bed. Dry feet thoroughly and put on socks to keep feet warm.
Rubbing hands and feet can improve micro-circulation in the capillaries. Adding certain essential oils, or ginger, chamomile, and cinnamon (not all in the same bath or foot bath) can help.
Acupressure or moxibustion on acupunctures points like zu san li, yong quan, he gu and nei guan can improve circulation and reinforce yang energy.
Keeping the core, the trunk, warm is necessary as this way the heart can pump blood further away to toes and fingers.
Black foods that reinforce kidney energy are recommended in winter to boost yang energy. They include black-feet chicken, black rice, black buckwheat, black beans, black sesame, dark jujubes and black fungus are among those recommended.
"Warm" (yang energy) foods activate blood circulation, including mutton and ginger.
TCM herbal teas and soups can adjust energy balance. Ingredients include dan shen (red sage root), rou gui (cinnamon), ginseng and dang gui (angelica root) - but not all in one pot.
Ginseng and walnut soup
Ingredients: Ginseng (7-8 slices), walnut halves (15-20)
Preparations: Boil with a little water to cover ingredients, boil quickly, simmer for 10-20 minutes. Drink often before sleep and eat ingredients as well.
Benefits: Helps reinforce healthy energy, warms the body, soothes nerves.