Your body is constantly losing fluids through breathing, sweating, and urinating. If you do not take in enough fluids, you may become dehydrated.
Your body may also have a hard time getting rid of fluids, allowing excess fluid to build up. This is called fluid overload.
Many illnesses can cause fluid imbalance:
- It is common to retain large amounts of fluid for several days after surgery (causing swelling of the body).
- In heart failure, fluid collects in the lungs, liver, blood vessels, and body tissues because the heart does a poor job of pumping it to the kidneys where it can be eliminated.
- When the kidneys do not work well because of chronic kidney disease, the body cannot get rid of unneeded fluids.
- The body may lose too much fluid due to diarrhea, vomiting, excessive blood loss, or high fever.
A fluid imbalance is often associated with imbalances of sodium, potassium (see: hyponatremia, hypokalemia, and hyperkalemia) and other chemicals that help regulate body fluids.