Yawning is said to be triggered by fatigue or tiredness, but new research from Britain claims that dehydration may be the primary factor. Researchers found that nearly one-fifth of patients who visit doctors report fatigue and extreme exhaustion. The survey was conducted by the Natural Hydration Council.

Dr. Roger Henderson, an adviser to the council, believes there are several reasons why some people may feel tired all the time, but a common cause is a lack of enough water in the body. Henderson further said that some people mistakenly believe they should drink water only when they feel thirsty. However, a National Health Service guideline says that women should drink at least 1.6 liters of water per day and men should drink two liters per day. Children should drink at least 6 to 8 glasses of water a day.

However, statistics reveal that on an average, nearly 60 percent of Britons drink less than a glass of water in a day. “Many of my patients do not drink enough fluid each day and only believe they are dehydrated when they start to feel thirsty. Yet other symptoms of dehydration appear before this, including fatigue and tiredness, headaches and poor concentration," Henderson said in a statement.

The link between fatigue and dehydration totally surprised patients. After people were asked to increase their daily water intake, nearly one-third felt less exhausted and tired.