Asthma directly affects the human body's respiratory system and, indirectly, the circulatory system.

At its core, the function of breathing is designed to take in oxygen from the outside and pass it on to the blood supply, by which oxygen is then delivered to the body's various organs. With each breath, in goes the oxygen and out goes the carbon dioxide. The mouth and nose take in the breath, while the trachea, lungs, and diaphragm pass on the inhaled air to the circulatory system. All of these elements can be slowed down by the condition of asthma.

Clogged Airways

The remarkable thing about asthma is that it can only be controlled, not cured. The trachea begins to produce extra mucus, complicating the simple act of breathing. For those with mild asthma, the condition may be nothing more than a slight nuisance. But if the asthma is severe, it can interfere with all sorts of daily activities and lead to further, major complications. Symptoms may include shortness of breath, coughing, chest tightness, chest pain, and wheezing

In some cases, the asthma is named for the setting in which it is triggered: exercise-induced asthma, occupational asthma, and allergy-triggered asthma. Other, broader asthma triggers range from cold air and air pollutants or airborne allergens to food preservatives and prescription medications.

Heat Waves

Years such as 1994 and 2011, with their many heat waves, have proven to be particularly bad in terms of general U.S. air quality. This is a critical trigger element for the respiratory system of asthma sufferers. Based on Environmental Protection Agency data, one of the worst areas in the United States for "code orange" days in 2011 at the summer, half-way point was the Southern California region of San Bernadino. Asthma sufferers there endured a total of 54 bad respirator days between January 1 and the beginning of August.

The EPA has been late with setting new ozone standards by which such measurements are gauged. In the summer of 2011, a federal lawsuit was filed by environmental and health groups to force the agency to stop delaying the announcement.