Tissue plasminogen activator (tPA) is a clot-dissolving enzyme that plays a vital role in the body's natural processes of coagulation and fibrinolysis. When there are excessive blood clots or thrombi blocking arteries such as those found during myocardial infarction (heart attack), stroke, or pulmonary embolism (lung obstruction by blood clots), tPA can help dissolve these blockages.

tPA works by converting plasminogen into its active form called plasmin. This process initiates the breakdown of fibrin and other components that make up thrombi, thereby restoring normal blood flow through affected vessels.

In addition to its use in emergency situations like acute myocardial infarction or stroke where timely restoration of cerebral perfusion is crucial for salvaging brain tissue; tPA also finds applications outside these critical care settings - such as management of large ischemic strokes within 3-4.5 hours post onset when administered intravenously along with other evidence-based therapies according to guidelines issued by relevant professional societies like American Heart Association/American Stroke Association (AHA/ASA).

However, it's essential to note that tPA should only be used under close medical supervision due to potential risks associated with its administration including but not limited to: bleeding complications ranging from mild epistaxis up until life-threatening intracranial hemorrhages; allergic reactions manifesting as anaphylactoid symptoms such as difficulty breathing or swallowing leading potentially fatal hypotension requiring immediate intervention by trained healthcare personnel on standby.

In conclusion, while tPA remains a valuable therapeutic agent within carefully selected patient populations under expert hands its judicious deployment is critical given inherent risks-benefits balance especially considering alternative management strategies available today making informed decision-making between different treatment modalities an essential component of modern evidence-based practice.