Catherine O’Hara’s Death Certificate Confirms Pulmonary Embolism, Cancer as Underlying Cause

Actor Catherine O’Hara died from a pulmonary embolism, with rectal cancer listed as the underlying long‑term cause, according to her newly released death certificate. The document states that the 71‑year‑old star died after a blood clot blocked an artery in her lungs, a condition her oncologist had been treating her for since March of last year. He last saw her only days before she passed away in a California hospital.

A pulmonary embolism typically occurs when a blood clot forms elsewhere in the body, often in a deep vein, and travels to the lungs. Symptoms can include chest pain, shortness of breath and fainting.

O’Hara’s death came as a shock to many. Initial statements described her passing only as the result of a “brief illness,” leaving fans and colleagues stunned. The Canadian‑born performer was beloved for her comedic brilliance, from playing the frantic mother in the Home Alone films to her Emmy‑winning role as Moira Rose in Schitt’s Creek.

Tributes poured in from collaborators and friends, including Macaulay Culkin, Christopher Guest, Eugene Levy and Pedro Pascal, all honouring her legacy and impact on generations of audiences.