Causes. Although doctors don't know what causes ITP, they know that it happens when your immune system -- your body's defense against disease -- doesn't work right. Your antibodies, which are supposed to attack infections, instead mistakenly destroy your blood platelets.
Although not as strong as the Asian monsoon, the cycle is typical of monsoon seasons worldwide. The monsoon season begins on June 15 and ends on September 30, but the storms peak between mid-July and mid-August. On average, about half of Arizona receives about half of its annual rainfall during the monsoon. However, rainfall can vary tremendously between distances of just a few miles.
The monsoon typically loses its energy by mid-September when drier and cooler conditions are reestablished over the region. Geographically, the North American monsoon precipitation region is centered over the Sierra Madre Occidental in the Mexican states of Sinaloa, Durango, Sonora and Chihuahua.