Anxiety is the displeasing feeling of fear and concern. It can be generalised or specific. Stress is the feeling of being under too much mental or emotional pressure. It is the mind projecting anxiety about a possible future event, such as missing an important deadline.  The two are closely related energetically, so they are dealt with together.

Anxiety and stress effect the Qi of the kidneys, there is stagnation of the flow of Qi, this in turn puts pressure on the heart. The speed of modern life, has a detrimental effect on the kidney Qi. It is conserved by a relaxed pace of life. The balance is always between the pressures of life and the speed in which the resultant emotions can be removed from the body. If the anxiety generated becomes too much, the flow of kidney qi will stagnate, this causes the feeling of stress many are so familiar with. If the stress is chronic, it puts pressure on the energy of the heart leading to depression, as  discussed in the page about depression. Stress can be seen as the first stage of depression.
This state is very treatable with acupuncture. First restore the flow of the kidney qi by creating fresh energy and directing it into the kidney system, usually this is all that is needed to bring about calm. The daily emotional cleaning process, which is natural and healthy in humans will continue and response to pressure stays within normal parameters, ie there will be no big reaction.