Serous fluids, or those that arise from the liquid portion of blood, may be found in any of the bodily cavities of the human body. Accumulations of these fluids in and around tissues may lead to severe consequences, especially that of heart failure, where fluids gather around the heart and affect the contractions of the heart. When fluids accumulate in the lungs due to infection, the ability to obtain oxygen from the environment and to expel waste gases from the body may be compromised and lead to critical changes in the body.