Dr. Ben Wedro practices emergency medicine at Gundersen Clinic, a regional trauma center in La Crosse, Wisconsin. His background includes undergraduate and medical studies at the University of Alberta, a Family Practice internship at Queen's University in Kingston, Ontario and residency training in Emergency Medicine at the University of Oklahoma Health Sciences 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.
Pulmonary edema literally means an excess collection of watery fluid in the
lungs. (pulmonary=lung +edema=excess fluid). However, the lung is a complex
organ, and there are many causes of this excess fluid accumulation. Regardless
of the cause, fluid makes it difficult for the lungs to function (to
exchange oxygen and carbon
dioxide with cells in the bloodstream).
Air enters the lungs through the mouth and nose, traveling through the
trachea (windpipe) into the bronchial tubes. These tubes branch into
progressively smaller segments until they reach blind sacs called alveoli. Here,
air is separated from red blood
cells in the capillary blood vessels by the microscopically thin walls of the
alveolus and the equally thin wall of the blood vessels. The walls are so thin
that oxygen molecules can leave air and transfer onto the hemoglobin molecule in
the red blood cell, in exchange for a carbon dioxide molecule. This allows
oxygen to be carried to the body to be used for aerobic metabolism and also
allows the waste product, carbon dioxide, to be removed from the body.
If excess fluid enters the alveolus or if fluid builds up in the space
between the alveolar wall and the capillary wall, the oxygen and carbon dioxide
molecules have a greater distance to travel and may not be able to be
transferred between the lung and bloodstream. This lack of oxygen in the
bloodstream causes the primary symptom of pulmonary edema, which is shortness of
Compression stockings can be helpful by increasing the resistance to fluid leaking out of the vessels. These can be purchased in any medical supply store, and are particularly useful for peripheral edema. Body positioning can also be helpful for both peripheral and pulmonary edema to ease symptoms. For example, elevating the head with pillows in bed may benefit someone with pulmonary edema, while elevating the legs may minimize ankle and/or leg edema.