Dehydration glossary

Dehydration: 10 Terms to Know

While mild forms of dehydration are easily treatable, more severe cases can turn deadly very quickly. Staying informed can act as a valuable preventative measure, so here are 10 terms related to the condition that you should know to stay safe. 

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This is often used as a blanket term when the fluid and electrolyte levels in the body are out of balance. Too many fluids and electrolytes are lost through bodily processes, while too few are taken in to replace them. There are several different terms that differentiate between the varying imbalances, however, and “dehydration” generally refers to a loss of both water and electrolytes, or isotonic dehydration. 


In hypernatremic dehydration, the body suffers a large loss of water but does not lose electrolytes as intensely. Although hypernatremia does refer to high levels of sodium, it is important to note that the levels aren’t raised because of too much intake. Rather, it occurs because of too little water to balance levels out. 


Hyponatremic dehydration refers to too little sodium in the body, which is normally caused by excess fluid diluting its levels. When people speak of the dangers of drinking too much water, this is generally the feared product of excessive intake. It is relatively rare, however, and it can be avoided. Experts recommend not drinking so much that the stomach feels full simply from having so much water in it. 


During dehydration, electrolytes are usually lost too. A variety of minerals—including salt, potassium, calcium, and chlorine, among others—make up electrolytes, which are responsible for carrying electrical impulses around to the muscles and other body parts. Dehydration alters electrolyte levels in the body, which in turn interrupts the carried signals, potentially causing seizures and other dehydration side effects.  

Hypovolemic Shock

As dehydration sets in, the skin seems to become shrunken, urine output decreases, and you may even be unable to sweat. Fluid is pulled from all parts of the body, including the blood. Hypolemia is a low blood volume, which means there isn’t enough blood to carry around oxygen and blood pressure falls. During hypovolemic shock, these levels reach dangerous lows.


Hypotension refers to the lowered blood pressure that occurs as a result of dehydration and hypovolemia. In turn, low blood pressure causes some of the other symptoms of dehydration, such as dizziness and confusion.


To diagnose dehydration, doctors sometimes perform blood tests. One of the signals of dehydration is hyperalbuminemia, which occurs when there is too much protein in the blood plasma. 


Although the color of your urine can be a good indicator of dehydration, doctors generally take a more technical approach. Thus, urinalysis is often used to diagnose dehydration. Highly concentrated urine means there isn’t as much fluid in it as there should be—leading to the dark amber shade that occurs during dehydration. 

Cerebral Edema

After long periods of dehydration, especially severe cases, the cells are often inclined to take in as much fluid as they possibly can, and sometimes that’s too much. The cells swell to such an extent that they burst. This is especially dangerous in the brain cells and can lead to cerebral edema, in which the brain itself swells up because of too much fluid. 

Oral Rehydration Solution

This simply refers to fluids made specifically for treating isotonic dehydration. This includes sports drinks that include not only fluid but electrolytes, as well as children’s drinks like pedialyte, that provide the body with additional electrolytes, vitamins, and minerals. 


Last Updated: October 04, 2017