Electrolyte replacement can make the difference between finishing a marathon and being transported to a hospital in critical condition halfway through the race. Electrolytes are small ions, or charged particles, that are essential for nerve and muscle function.

Your body is about two-thirds water. Dehydration reduces the amount of water in your body. Severe dehydration can lower blood pressure and the amount of oxygen available to your cells, which may lead to coma and death.

When your body loses more water -- through urination, tears, sweat and respiration -- than it takes in, you can become dehydrated. You can also lose fluids when you are sick and vomiting or experiencing diarrhea.

If you've ever been so thirsty that no amount of water seems to slake that thirst, chances are there is something going on inside your body that needs to be evaluated by a health-care provider. The headache might be caused by the unquenchable thirst and should be added to any list of symptoms you're giving.

Even mild to moderate dehydration can create potentially damaging consequences to your body during exercise. Not drinking enough fluids or losing too much bodily fluid causes dehydration.

Dehydration synthesis is the process of making a larger molecule from smaller building blocks by removing two hydrogen atoms and one oxygen atom -- the chemical components of water.

Dehydration is the loss of fluid from the body. There are many reasons for dehydration, including heatstroke, strenuous exercise, kidney disease, vomiting and diarrhea, and chronic conditions like diabetes. The symptoms of dehydration include dry lips and mouth, rapid heart rate and decreased urine output.

Several conditions can cause decreased appetite and increased thirst. According to the University of Maryland Medical Center, or UMMC, increased thirst, also known as polydipsia, is a fairly common symptom.

A food dehydrator is a kitchen appliance used for drying food. Dehydration is a method of food preservation, in which moisture is removed from the food. Drying food extends the shelf life of a food by decreasing growth of bacteria and minimizing spoilage.

Creatine is a natural amino acid your body produces, but it’s also available over-the-counter as a supplement. According to the University of Maryland Medical Center, creatine supplements make up a $14 million industry in the United States alone.

Severe dehydration is a life-threatening medical condition caused by excessive fluid loss from the body. You can develop dehydration due to illness, prolonged exposure to heat or by simply not drinking enough fluids. Contact your doctor immediately if you develop any of the symptoms of severe dehydration.

Dehydration occurs when the amount of water leaving the body is greater than the amount being taken in. This can be a serious condition for anyone, but particularly for young children under the age of 2.