Headaches have many triggers. Muscle tension, nighttime teeth-grinding, stress and anxiety, bright lights, and some food ingredients are just a few examples.
Dehydration can also cause headaches. The body becomes dehydrated when a person does not drink enough fluids to compensate for water lost in urine, sweat, and breathing. The concentration of ions in body fluids therefore climbs, drawing water out of body cells by osmosis and impairing their function.
The infamous “hangover headache” associated with a night of heavy drinking is likely a result of dehydration. The cause-andeffect relationship between alcohol consumption and dehydration originates at the kidneys. Normally, when the concentration of solutes in blood is too high, the brain releases a hormone that stimulates an increase in the number of water-transporting aquaporins in kidney cell membranes. The kidneys return more water to the bloodstream, so urine production declines.
Alcohol, however, interferes with the “water conservation” hormone. The kidneys produce fewer aquaporins and more urine, and the body becomes dehydrated. A headache soon follows. To prevent or cure this painful side effect, experts recommend drinking more water, both with the alcohol and after the merriment ends.