The body requires the proper balance of fluid and electrolytes to function properly. Every day, the body loses water through daily activities, such as sweating and urinating. Most of the time, the amount of fluid lost is easily balanced through drinking or eating fluid-rich foods. However, sometimes the body loses water faster than it can be replenished.
Symptoms
A dehydration headache can feel like a dull headache or an intense migraine. Pain from a dehydration headache can occur at the front, back, side, or all over the head. Unlike a sinus headache, a person experiencing a dehydration headache will likely not experience facial pain or pressure. Pain is also unlikely to occur in the back of the neck as it might with a tension headache.
Since dehydration headaches only occur when the body is dehydrated, symptoms of dehydration will occur with the headache. These symptoms include the following:
extreme thirst
reduced urination
dark colored urine
confusion
dizziness
fatigue
dry, sticky mouth
loss of skin elasticity
low blood pressure
increased heart rate
Some people may only experience a dehydration headache if they are severely dehydrated. These people may not only have a headache and some of the above symptoms but also experience some further symptoms.
What is Dehydration
Although there is no absolute definition, dehydration is typically defined as depletion in total body water content due to fluid losses, diminished fluid intake, or a combination of both. Depending on the ratio between sodium and water losses, dehydration can be classified as isotonic (equal loss in sodium and water – example: diarrhoea), hypertonic (excess loss of water compared to sodium – example: fever) or hypotonic (excess loss of sodium compared to water – example: overuse of diuretics)
Water-loss While Aging
As one ages, the total body water content declines, due to a decrease in lean body mass and an increase in percentage of body fat (a tissue poor in water) (Sheehy et al. 1999). Four to six liters of total body water can be lost from the age 20 to the age of 80.