Your body is estimated to be about 60 to 70 percent water. Blood is mostly water, and your muscles, lungs, and brain all contain a lot of water.
You need water to regulate body temperature and to provide the means for nutrients to travel to your organs and tissues. Water also transports oxygen to your cells, removes waste, and protects your joints and organs.
Signs of Dehydration
You lose water through urination, respiration, and by sweating, and you lose more water when you're active than when you're sedentary. Diuretics, such as caffeine pills, certain medications and alcohol may increase the amount of water your body loses. Energy drinks with large amounts of caffeine may also have a diuretic effect. Most caffeinated beverages like coffee and tea don't appear to have much of a diuretic effect. Lost fluids must be replaced by the fluids in the foods you eat and the beverages you drink.
If you don't get enough water, you may suffer from hydration. Symptoms of mild dehydration include chronic pains in joints and muscles, lower back pain, headaches and constipation. A strong odor to your urine, along with a yellow or amber color, may indicate that you may not be getting enough water. Note that riboflavin, a B vitamin, will make your urine bright yellow when you take dietary supplements that contain large amounts of riboflavin. Certain medications can change the color of urine as well. Thirst is an obvious sign of dehydration, and in fact, you need water before you feel thirsty.
How Much Do You Need to Drink?
Some experts believe you can estimate the amount of water you need by taking your weight in pounds and dividing that number in half. That gives you the number of ounces you may want to drink each day. For example, if you weigh 160 pounds, you might want to drink at least 80 ounces of water or other fluids per day. Other factors include amount of physical activity and the climate where you are located. My water calculator can help you determine how much water you need to drink each day.
At least twenty percent of the water you need comes from the foods you eat. The rest comes from the beverages you drink. Water is probably the best choice because it's cheap and has no calories or added ingredients. Sweetened soft drinks and sodas have added sugar that adds extra calories but no additional nutritional value. Sports drinks contain minerals that may help keep your electrolytes in balance, which is good for recovering after a hard work out, but look out for added sugar and calories that you may not want. Fruit and vegetable juices can be a good choice because they have vitamins and minerals your body needs (read labels, however -- vegetable juices may be high in sodium). Caffeinated beverages like tea and coffee count too, but too much caffeine can make you feel jittery.