Spring is warm, eat wheat to cool it,
Summer is hot, eat beans to cold it,
Autumn is dry, eat sesame (seeds) to lubricate it,
Winter is cold, eat corn to warm it.
The External Factors – Seasonal Excesses
The conditions that upset our body’s balance can be external or internal. The external factors are wind, cold, summer heat, dampness, dryness and fire. They are all induced by the change of season and climate. They are also known as the six excesses or the six evils. They invade our body through the mouth, nose or skin. If the excesses are not suppressed quickly, they can become internal excesses and the problems are more difficult to treat.
The understanding of the seasonal excesses is important in preventing sickness and maintaining health. When the body's immune system is low and is being attacked by these climatic changes, it upsets the internal balance and causes sickness.
Spring is the time of wood and is the season of wind excess. The gusty wind scatters seeds around and brings about a new season of growth. Our bodies undergoing new development in spring require blood and energy from the liver to support its growth. With the liver working extra hard at this time, it is most vulnerable to external wind injury. Excessive wind can also result in other problems such as cold/flu, headache, muscle pain and skin allergy. When external wind travels inwards, it causes problems such as vertigo, tremor, headache, seizure and stroke, which are internal wind injuries. Their typical symptom is the moving of pain around the body.
Summer is the time of fire and is the season of heat excess. It is the peak-growing season of lives on earth. The effects on humans are acceleration of metabolic rate, dilation of blood vessels and increased speed of circulation. When heat becomes excessive, inflammation, rapid pulse and fever occur. Hot conditions are also associated with thirst, dryness, constipation, difficult urination, agitation and desire for cold drinks and cooler temperature. When heat invades the surface of our bodies, profuse perspiration, skin eruption, red face and eyes occur. When it gets internal, it affects our emotions and results in anger and rage. The heart is associated with fire and is most vulnerable for attacks in summer.
Late summer is earth and is the season of dampness excess. Dampness is like stagnant water, which sinks and accumulates. It causes heaviness and swelling to the body, which can obstruct circulation. External dampness results in oily skin, sticky perspiration and swelling around the joints. Internal dampness results in the loss of appetite, indigestion, phlegm, abundant discharge of mucus, water retention and edema of the abdomen and extremities. The lingering influences of dampness are difficult to shift and can last for a long time. It attracts other evils such as cold, heat or wind to attack the body. Late summer is associated with our spleen system and it has to work extra hard to expel excessive dampness from either the climate or our diet in order to function properly.
Fall is the time of metal and is the season for dryness excess. When dryness dominates the atmosphere, it irritates our lungs and causes respiratory problems. It exhausts our internal fluids and causes dehydration. External dryness results in brittle hair and nails, cracked and wrinkled skin, irritated eyes, dry cough and asthma. Internal dryness causes dry stool and constipation, scanty urine, loss of fluid and blood. Our lungs are most vulnerable to dryness attacks. It is important to eat moisturizing foods in fall in order to promote the production of vital fluids for lubricating the lungs and other internal systems.
Winter is water and is the season of cold excess. When our body is attacked by external coldness, it shivers, slows down and has sharp pains. The body produces clear and transparent mucus. When coldness turns internal, it blocks the flow of blood and qi, suppresses metabolism and circulation. Consuming excessive cold food damages internal yang energy and causes deficient metabolic heat. The most common consequences are weakness in the digestive system and the immune system. It is important to stay less active in winter in order to preserve yang energy. The kidney is the organ that produces and stores yang energy and is most vulnerable to attacks at this time. The damage to the kidney causes premature aging, impotence and infertility.