Mild Dehydration Causes Anger, Fatigue and Mood Swings, Study Reveals

Angry? Drink A Glass Of Water

If you feel a sudden surge of anger, there may be an underlying reason why you’re losing your cool - thirst.

Dehydration affects cognition, concentration and the general ability to think clearly and control mood, a group of scientists have discovered.

Researchers from the University of Connecticut’s Human Performance Laboratory found that even mild dehydration alters a person’s mood, energy levels and mental function.

The study involved putting dehydrated participants through a series of cognitive tests measuring vigilance, concentration, memory, reasoning and learning ability. The results compared against those who were not dehydrated.

Researchers discovered that mild dehydration, particularly in young women, caused headaches, fatigue and difficulty concentrating. Female participants struggled concentrating on simple tasks but interestingly, suffered no reduction in cognitive ability.

Dehydrated young men on the other hand, experienced difficulty in mental tasks, especially in areas of vigilance and memory, as well as anxiety and tension.

Alterations in mood were "substantially greater in women, both at rest and during exercise," explains co-author of the study, Harris Lieberman, in a statement.

“Even mild dehydration – 1.5% loss in normal water volume in the body – that can occur in the course of our ordinary daily activities can degrade how we are feeling, especially in women, who are more susceptible to the adverse effects of low levels of dehydration.”

Researchers added that the adverse effects of dehydration didn’t vary between those who just exercised for 40 minutes or those sitting down at a desk.

"Dehydration affects all people, and staying properly hydrated is just as important for those who work all day at a computer, as it is for marathon runners, added Lieberman.

Adding to this, fellow author, Lawrence E. Armstrong, says: "Our thirst sensation doesn’t really appear until we are 1 or 2% dehydrated. By then dehydration is already setting in and starting to impact how our mind and body perform."

The study was published in The Journal of Nutrition.

Dehydration happens when the body loses more fluid than what goes in. When the normal water content of the body is reduced, it upsets the balance of minerals, like salts and sugars, in the body, which affects the way it functions.

Water makes up over two thirds of the human body and it lubricates the joints and eyes, as well as aiding digestion, flushing out toxins and waste and keeps skin healthy.

Symptoms of dehydration include feeling thirsty or lightheaded and having dark coloured, strong-smelling urine.

Many studies have tried to establish a recommended daily intake of water but it varies on the individual and other factors like age, climate and physical activity. In general, a healthy water intake is around 1.2 to 2 litres per day (6 to 8 glasses).

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