Congestion of the lungs, or pulmonary edema was fluid accumulation in the air spaces and parenchyma of the lungs.
In 2269, Doctor Leonard McCoy suffered congestion in both of his lungs after being tortured by the Vians. (TOS: "The Empath")
In 2375, Vargas was suffering from chest congestion, which Doctor Julian Bashir later treated with 20 ccs of numinol tetraminothen. (DS9: "The Siege of AR-558"}