There are two forms of =edema=, collateral and general, which follow
an intense congestion with transudation of serum into the air vesicles
and interstitial tissue. The =collateral form= is localized and
usually appears in connection with pneumonia, pulmonary infarction
or abscess. In =general edema= the base of the lung is involved to a
greater extent, but the whole structure is affected and hydrothorax is
generally present. The =cause= of edema is not well understood, but may
result from a long line of constitutional diseases. The =symptoms= are
dyspnea, cough with copious, blood-streaked sputum which is expelled
with difficulty. There may be fever in the inflammatory type with weak,
increased pulse. Dullness over the affected area, broncho-vesicular
breathing and small liquid rales are audible. The =diagnosis= must
largely be made upon the bilateral dullness at the base of each lung
and physical signs noted above. X-ray examination will usually be of
value. =Prognosis= depends on the condition causing the edema and
treatment should be directed to correcting it. Frequently edema is a
terminal affection. This should be followed by osteopathic treatment to
free the lungs of the effusion as outlined under pneumonia, especially
relaxation of the upper dorsal and cervical muscles, separation of the
upper ribs and stimulation of the heart.