According to Traditional Chinese Medicine, wei (or defensive qi) is located on the surface of the skin.
When the wei is strong, viruses and bacteria cannot penetrate the body. When it is weak, the body is
susceptible to a variety of infections. Therefore, prevention from illness relies on the normal functioning
of the wei qi.

Nutritional

Vitamins A, C, E and Zinc are essential in promoting a healthy immune system
Drink plenty of fluids
Eat foods that strengthen the body and fight off infection, (e.g. garlic, citrus fruits, green vegetables)
Limit the intake of refined sugars; they impair the body’s ability to kill bacteria and fight off infection
Specific Chinese herbs taken regularly can provide protection against foreign or pathogenic factors


Lifestyle Tips

Avoid over exertion, both mentally and physically
Wear appropriate clothing on cooler days
Be sure to have adequate sleep
Regular physical activity can help you prevent or manage a wide range of health problems and concerns, including stroke, metabolic syndrome, type 2 diabetes, depression, certain types of cancer and arthritis.

References:
Clinical Manual of Oriental Medicine; An Integrative Approach (2nd ed.). (2006). City of Industry, CA: Lotus Institute of Integrative Medicine.

Acupuncture & IBS. Acupuncture Media Works. (2012). www.acupuncturemediaworks.com.