Sudden extensive bloody pleural and pericardial effusion in a subject with untreated known hypothyroidism after total thyroidectomy, triggered by pneumonia.

In subjects with hypothyroidism, fluid and mucopolysaccharide are stored in interstitial space and protein osmolality is increased, thus leading to edema and fluid retention. It is noted here that pleural effusion and pericardial fluid in this subject showed bloody color and included red blood cells. There are no reports of bloody pericardial fluid with hypothyroidism. Therefore, it is important to keep in mind that a subject with some trigger, such as infection, may have a hematologic fluid retention that is not seen when hypothyroidism is present alone, as observed in this subject.