Without water, we can't survive, and we can only live roughly three days without it. 

Water literally keeps us alive. We need it for our cells to function, organs to work, brain health, pH balance, elimination of toxins, lubrication of joints and spinal cord, oxygen transportation, digestion and the moistening of mucous membranes. 

Even mild dehydration can lead to impaired cognitive function causing things like driver errors. As little as two hours or 2% dehydration can weaken brain function, affecting attention and executive functions like planning, reasoning and problem-solving. It can also negatively impact motor coordination and reaction times.

Signs that you are dehydrated include thirst, headache, bad breath, lethargy, dark coloured urine, muscle fatigue, and dizziness. More chronic symptoms can be dry skin, constipation, frequent headaches, constant tiredness and continued muscle weakness. 

If your urine has a pale yellow colour, then you should be adequately hydrated. You can also try the pinch skin test if you're worried your hydration levels are low.

Here are some common mistakes that can lead to dehydration.