Headaches... Our brain is over 75% water and when it detects a shortage of available fluids it implements a water rationing process by producing histamines‚ causing pain and fatigue. This natural process is meant to slow us down and conserve water. Histamines are released as a warning signal that something is wrong. When we take antihistamines or analgesic medicines like acetaminophen or ibuprofen we simply turn off the signal and often allow the problem to progress. Two cups of water and a 20 minute break will overcome most common headaches.