The 5 Elements: the fifth Element is Water

Water is the element of the kidneys and the urinary bladder, and rules  the bones.
The emotion related to the kidneys is fear and fright: if you are always afraid of things, you bet your kidneys are in trouble.

The sound related to the water element  is groaning. Salty is the taste related to water. The ears and hearing are influenced by the health of the kidneys. 

In nature we see water as cold, as winter, as storing, as black/dark, as salty, as north and the earth "grains" are beans.
During winter time we should pay special attention to the kidneys: winter time is time for less physical activity, to go to sleep early, to meditate.

We also advice stretching to keep the spine and joints flexible: everyone, whatever the age, should be able to bent forward and touch the ground with the palms of the hands.

For foods you should choose hearty soups and stews, whole grains, roasted nuts, dried foods, small beans, seaweeds and steamed winter greens. Cook food more Yang (longer, at lower temperature, and with less water). If salty is the taste of winter, it is still dangerous to add too much salt in your food, so please keep it balanced, as you already have salt when you eat seaweed.
Bitter foods will do well too; endives, celery, sometimes chicory root, burdock root, etc.

As I wrote for the wood element: if the liver and the kidneys are perfect, your life will be perfect, as they influence the other organs a lot! 
When the kidneys are healthy, we are calm but active, courageous but gentle, accomplishes a great deal without stress.