Ruchi Mathur, MD, FRCP(C) is an Attending Physician with the Division of Endocrinology, Diabetes and Metabolism and Associate Director of Clinical Research, Recruitment and Phenotyping with the Center for Androgen Related Disorders, Department of Obstetrics and Gynecology at Cedars-Sinai Medical Center.
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
The balance and regulation of fluid in the body is very complex. In short,
the cause of edema as simply defined as possible, is that tiny blood vessels in the body
(capillaries) leak fluid into the surrounding tissues. This excess fluid causes
the tissues to swell.
The cause of fluid leaking into the surrounding tissues may be the result of
several mechanisms, for example:
too much force, or pressure inside the blood vessels;
a force outside of the blood vessel causes the fluid to be drawn through
the wall of the blood vessel is compromised and cannot maintain
Each of these three mechanisms may be associated with a variety of diseases
or conditions. Examples include the following.
Pregnancy: Edema during
pregnancy may occur because
pregnant women have a
greater volume of fluid circulating in the body, and because they also retain
more fluid. A woman may also experience
Medications: Edema may be caused by a variety of medications, for
example, steroids, calcium
channel blockers (CCBs), thiazolidinediones,
drugs (NSAIDs), estrogens, etc.).
Liver disease and/or kidney disease:
Both of these organs are vital in maintaining
fluid balance in the body, and if severe disease is present in either of these
organ systems, edema can develop. Examples include:
cirrhosis of the liver,
chronic kidney disease,
and acute kidney failure.
Venous insufficiency: This is a common condition in
which blood does not return to the heart efficiently from the peripheral areas of the body (for
example, the ankles,
legs, feet, hands), which results in edema. This typically results in edema in
Heart failure: If the heart is weak and cannot pump blood efficiently,
blood will pool in particular areas of the body, which will cause fluid to leak
from the blood vessels into the surrounding tissues.
If the right side of the heart is weak, pressure will build in the
peripheral tissues in the body (hands, ankles, feet, legs). This is referred to
as peripheral edema.
If the left side of the heart is weak, pressure will
build in the lungs, causing pulmonary edema.
Idiopathic edema: Accumulation of fluid in surrounding tissues with no
identifiable cause is referred to as idiopathic edema.