Sportsmith Blog

Dehydration The Sign and Symptoms

Considering the human body is made up roughly of 70% water, drinking fluids on an ongoing basis is necessary for maintaining bodily functions and preventing dehydration symptoms.  Reality is, most people do not drink enough water throughout the day.  Although the amount needed is dependent on body weight, general rule of thumb is to drink at least eight glasses of water daily.

Dehydration occurs when more water is lost from the body than is taken in.  Water is lost routinely each day through the processes of breathing, sweating, urination, and elimination. While water is found mostly in body cells, the rest is distributed in blood vessels and in spaces between the cells.

Water balance in the body is so critical and so well-regulated that if water is lost from blood vessels, this loss is automatically replaced by moving water from cells into blood vessels. Signs and symptoms of dehydration occur quickly if this loss of water is not replenished. The first recognizable sign is thirst; the body is getting dry and needs a drink of water.

Causes of Dehydration:

Sweat - People lose water through sweating; exercising intensely; or fever due to an infection.  A person can lose a pound of water just by taking a brisk walk on a hot day. It is important this loss be replaced as quickly as possible.

The Elderly - Older people are quite vulnerable during heat waves, as they tend to thirst more slowly and are less likely to recognize signs of dehydration. In the Chicago Heat Wave of 1995, approximately 600 people died in their homes from heat exposure.

Illness - When illness strikes and people are dealing with vomiting or diarrhea, a great deal of water is lost from the body.  It is difficult to hold down fluids with bouts of vomiting.  As for diarrhea, 4 million children die each year, worldwide, from effects of dehydration.

Diabetes - For people who are diabetic, when blood sugar levels are high, sugar tends to draw water, making its exit through the process of urination. Therefore, having diabetes often involves frequent thirst and frequent urination, making it easier to become dehydrated.

Extreme Fluid Loss - This can come about through conditions of cholera (from contaminated water/food), resulting in vomiting/diarrhea and consequent dehydration. Bulimia (purging) can cause dehydration, as well as the excessive use of diuretics (water pills), along with a low-salt diet.  Stomach flu lasting 36 hours can also cause extreme water loss.

Signs and Symptoms of Dehydration:

Initial signs of dehydration are thirst and a decreased output of urine.  At this stage, urine becomes more concentrated and is yellow in color.  In addition, a person can experience dry mouth; weakness or fatigue; dry skin or flushing; head rushes or chills.

A 5% fluid loss can result in symptoms of:

*Increased heart rate/respiration/body temperature

*Decreased sweating/urination

*Extreme fatigue/headache


*Muscle cramps or tingling in the limbs


A 10% fluid loss constitutes severe dehydration and requires immediate medical attention. Symptoms associated with severe dehydration are:

*Pale, cool, clammy skin or shriveled skin

*Difficulty breathing, racing pulse

*Chest and abdominal pain, muscle spasms

*Low blood pressure, loss of valuable electrolytes

*Seizure, unconsciousness, organ failure, even death (the brain is most vulnerable to dehydration)


The best way to prevent dehydration is to drink consistently throughout the day (eight glasses minimum). An infant is considered well-hydrated if the diaper is wet at every change.

Avoid doing outdoor activities in high temperatures; hold events under shaded areas.  If you must work in a hot environment, hydrate frequently to replenish water loss.

When suffering from vomiting or diarrhea, change one's diet or use medications to control the degree of fluid loss. When recovering from such symptoms, clear fluids are usually recommended for the first 24 hours.  Then one should progress to what is called a BRAT diet, starting with bananas, then rice, apples and toast, in that order.  Add more foods when tolerated.

Imodium can be taken to control diarrhea; acetaminophen or ibuprofen to address fever.

Symptoms of dehydration can differ from person to person, as well as from differing ages.  Children lose more fluids through vomiting and diarrhea than adults, while the elderly are more prone to fluid loss than younger adults.


Why Staying Hydrated is Important

If you were told that the key to health and wellness lies in a tall glass of tap water, you probably wouldn’t believe it. Yet there’s perhaps more truth to this statement than meets the eye.

For instance, when you’re feeling irritable, drowsy or unable to concentrate, there’s a strong probability that your body is telling you its thirsty. Other early signs and symptoms of mild dehydration, explains Lisa De Fazio MS, RD, include headaches, reduced muscle performance, muscle cramps and dry eyes.

For competitive or recreational athletes, a mere two percent dehydration level can reduce performance by as much as 10 percent, states Amy Goodson, MS, RD, CSSD, LD, a sports dietitian in the Dallas/Fort Worth area and member of the Dallas Dietetic Media Bureau. Clearly the importance of hydration is nothing to balk at.

So what can you do to prevent dehydration, and how much water should you consume daily? Let’s take a closer look.

What is dehydration?

A whopping 60 percent of your overall body weight is water, and several organs and muscles contain as much as 80 percent. Dehydration occurs when the body lacks the proper amount of water necessary to perform physically, physiologically and mentally. Mild dehydration occurs when you lose just one liter of water. If you experience an increased heart rate, changes in blood pressure or thicker blood, you could be showing signs of moderate to more severe dehydration.

Several biochemical and physiological cellular reactions require both water and electrolytes, like chloride, calcium, magnesium, phosphorus, potassium and sodium in balance. Electrolytes make you feel thirsty which, in turn, promotes fluid intake and hydration. Carbohydrate metabolism keeps us active and productive. Without the proper balance, you will feel unusually sluggish and lethargic.

A healthy, adequately hydrated individual should have clear or pale urine, but an obvious sign of dehydration is urine closer in color to apple juice or oil. Dehydration is more common during hot summer months, in the morning immediately after waking, during tournaments, two-a-day training sessions or following lengthy periods of exercise.

How much water do you need?

Actual quantity of daily water intake varies for each individual based on age, weight, weather and attire, illness, and both the duration and intensity of exercise. However, generally speaking, Ms. De Fazio recommends eight to nine glasses of water per day on average to replace fluid expenditure from kidney filtration, respiration and perspiration.

If you consume milk or alcoholic, caffeinated or carbonated beverages, which are dehydrating, your body’s water requirement will increase. The same holds true during episodes of consistent exercise, during which you should consume 5 to 10 ounces of fluid every 15 to 20 minutes.

What’s the best way to hydrate?

Hydration comes in several forms, but plain water is, without a doubt, the best and most cost-effective option. One downside to water, however, is that it lacks the carbohydrates you need for energy and glucose replacement. Water also lacks the proper balance of electrolytes, like sodium and potassium, required during intense exercise sessions, Ms. De Fazio explains. Carbohydrate and electrolyte replacement is critical for athletes because they are naturally more prone to heat-related illnesses such as heat stroke or vomiting.

Soup, tea, smoothies, vegetables, juices, jell-o, decaffeinated coffee, fruit and low-calorie beverages like crystal light drink mixes also provide an excellent means for re-hydration, some of which also include electrolytes and carbohydrates, to help you prevent health consequences. Popular sports drinks like Gatorade, Propel, Powerade and Vitamin Water replenish the body during moderate to intense periods of physical exercise, boosting energy and performance. Just remember a sports drink is designed for sport, not for sitting behind a desk or math class, explains Amy Goodson, MS, RD, CSSD, LD. Then you should rely on water.

Steer clear of juices and soft drinks containing excessive amounts of sugar especially during physical activity or exertion as they can upset your stomach. Gatorade brand sports drinks contain measured sugars and carbohydrates ideally balanced to absorb quickly, replace lost glucose, boost athletic energy and ensure proper hydration even during peak temperatures. If you would rather eat your electrolytes as opposed to drinking a high-calorie sports drink, consider the following food sources paired with a tall glass of water:

Sodium Food Sources: baked chips, pretzels, crackers, soups, beef or turkey jerky

Potassium Food Sources: bananas, avocadoes, strawberries and potatoes

While water may not be the sole key to health and wellness, hydration is an essential element to feeling your best and performing at your peak.