In Four Pillars astrology, the presence of lots of Fire and Water elements in the horoscope often is considered to suggest heavy disease, and sometimes even cancer. In Chinese astrology this kind of clash between Fire and Water is called "War between Water and Fire" (shui huo xiang zhan) 水火相战 .
If one has a weak Fire and too much Water in the chart, then the Water will extinct the Fire. If the water is weak and the Fire is too strong in the chart, then the Fire will self-burn and cause different problems.
A balance between Water and Fire is needed in order to achieve a harmony in the chart. In TCM and Chinese astrology this is called: "Coordination between Water and Fire" (shui huo ji ji) 水火既济.
How to achieve this coordination? In respect of Chinese astrology, the Wood element is needed to smooth and coordinate the relations between Water and Fire. In this way, it is achieved a good flow of energy among the elements (from the cycle of mutual creation of the five elements): Water - Wood - Fire.
In a case that there is no Wood in the horoscope, then the Wood element could be supplemented by the means of Feng Shui or through other ways - increasing the presence of green color in the house, adding some green plants, eating more food and herbs, which can supplement the Wood element and balance the energy of Fire (Heart) and Water (Kidneys). No wonder that green herbs like dandelion, plantain and purslane have been proven to possess anti-cancer properties.