The Importance of Hydration

Hydration is necessary to quench thirst, regulate body temperature, keep muscles lubricated and help deliver nutrients to cells. Keeping the body well-hydrated also helps prevent dehydration, which can cause thirst, dizziness and headaches.


For most healthy people, drinking six to eight 8-ounce glasses of water each day is sufficient. You can also monitor your hydration status by checking the color of your urine. Dark-colored urine indicates dehydration.

Decreased Risk of Disease

Your body contains trillions of cells, and each of these cells requires water to function properly. Your cell membranes are permeable to water, and water flows into the cells of your body following osmotic gradients, which are created by differences in concentrations of solutes — such as sodium — on each side of the cell membrane.

Dehydration occurs when you do not drink enough fluids. When you are dehydrated, your heart rate may increase and your blood pressure can fall, leading to a number of serious conditions such as heat stroke or brain damage.

Optimal hydration is also essential for cognition. Mild levels of dehydration can cause problems with your ability to think clearly and concentrate, especially in hot weather or during exercise.

Although anyone can become dehydrated, infants and children are at a greater risk because they do not know how to communicate that they are thirsty. Older adults also tend to be more susceptible to dehydration because they are less likely to consume liquids. Evidence supports the role of good hydration in reducing the occurrence of urinary tract infections and hypertension but more research is needed.

Increased Energy Levels

Water is a non-caloric source of energy and is especially important during physical activity. Studies show that people are more energetic and perform better when they are hydrated. Athletes should make sure to drink water or a sports beverage with electrolytes before, during and after their workouts to maximize their performance.

Water promotes healthy hydration in the brain, bones and skin. In addition, it helps to relieve feelings of tiredness and fatigue by helping the body carry oxygen to the brain and cells. It also works to protect the spinal cord and lubricate joints.

Many people avoid drinking water because they believe it will increase the urge to urinate, which could lead to dehydration. However, the fluid loss from urination is minimal and the combined water intake of food and thirst-driven drinking is typically sufficient to maintain normal hydration levels. People who exercise intensely or who experience diarrhea or fever should drink more water to ensure adequate hydration. It can help to keep a water bottle with you at all times to encourage drinking habits and to help prevent dehydration.

Reduced Risk of Heat Stroke

When your cells lack sufficient water, they become stiff and unable to move freely. This prevents them from carrying out key metabolic functions, like generating energy or maintaining body temperature.

Heat stroke is an emergency condition that can cause brain damage, kidney failure and organ failure. You can reduce your risk of suffering this serious health complication by drinking plenty of water, especially if you are in hot weather or exercising.

A dehydrated body cannot sweat properly, and this can increase your risk of heat exhaustion and/or heatstroke. Dr. Sinha likens a dehydrated body to a car engine without coolant: it will stop functioning properly and eventually seize up.

Drinking water or cool sports drinks that contain salt and sugar can help you stay hydrated. It is also important to make sure that your water supply is clean and safe by having it tested by a Culligan Man. Certain medications can affect your ability to hydrate and respond to heat, including medicines that narrow blood vessels (vasoconstrictors), lower blood pressure by blocking adrenaline (beta blockers) or rid the body of sodium and water (diuretics). Children, older adults and people with chronic health conditions such as heart disease are at greater risk of developing these heat-related problems.

Smoother-Moving Joints

Most people know that adequate hydration is important for muscle and joint health. Adequate fluid intake lubricates joints, decreases inflammation and reduces friction in cartilage, which allows for smooth movement.

Cartilage in the movable joints of the body is comprised of 70-80% water. When the cartilage is hydrated it is soft and pliable, which helps to cushion the bones in the joint and allows for easier movement. However, when cartilage is dehydrated it becomes stiff and presents more friction when moving. The best way to prevent dehydration is by drinking plenty of water throughout the day.

However, it is also important to monitor how much water you drink to ensure that you are not over-hydrating. Over-hydration can cause the kidneys to flush too much sodium, which may result in a low concentration of sodium in the blood (hyponatremia). This condition is characterized by symptoms such as headache, muscle spasms and fatigue. Avoid this by consuming electrolyte-rich beverages, such as milk and watermelon, along with your daily dose of water. A good way to measure your hydration is by paying attention to the color of your urine. The darker the urine, the less hydrated you are.

Increased Tolerance to Hot Temperatures

Keeping yourself adequately hydrated allows you to maintain your ability to perform in hot conditions. Studies have shown that when dehydrated, mental acuity and motor control decrease, as do decision-making abilities and concentration. Gastric emptying is also slowed down, and the heart rate rises to compensate for the low blood volume. Fluid replacement during exercise can prevent this hydration deficit and improve performance in high temperatures by helping to prevent excessive elevations of heart rate and body temperature.

When you’re hypohydrated, water redistributes primarily from the intracellular to the extracellular space of muscle and skin. This increases osmotic pressure within cells, drawing more water into the cells and increasing their size. This reduces cell functioning, leading to a decrease in your tolerance to heat stress. One study found that drinking a metered amount of milk following thermal dehydration prevented exhaustion from exercise in the heat. The authors credited milk’s natural electrolytes, carbohydrates and protein for this effect. Several other research groups have reported similar findings using different beverage types. These results are consistent with the idea that drinking beverages other than water may be useful in preventing dehydration during prolonged exercise and other activities.