Athletes Asthma caused by low levels of sweat, saliva and tears

People who suffer from a form of asthma caused by exercise appear to produce less sweat, saliva and tears than people without the problem, researchers say.

The findings may shed light on a condition known as exercise-induced asthma, which occurs in some people when they exert themselves in cold air.

Writing in the September issue of Chest, the researchers, led by Dr. Warren Lockette of the Naval Medical Center in San Diego, noted that the low levels of moisture found in cold air appeared to play a role in exercise-induced asthma. As the airways dry out, they become inflamed.

When your asthma symptoms become worse than usual, it is called an asthma episode or attack. During an asthma attack, muscles around the airways tighten up, making the airways narrower so less air flows through. Inflammation increases, and the airways become more swollen and even narrower. Cells in the airways may also make more mucus than usual. This extra mucus also narrows the airways. These changes make it harder to breathe.

Asthma attacks are not all the same—some are worse than others. In a severe asthma attack, the airways can close so much that not enough oxygen gets to vital organs. This condition is a medical emergency. People can die from severe asthma attacks.