A newly issued Los Angeles County death certificate has confirmed that Emmy-winning actor Catherine O’Hara died of a pulmonary embolism, with rectal cancer listed as the underlying cause. The 71-year-old star died on 30 January in Santa Monica, with the document noting that she had been undergoing cancer treatment since March last year and was last seen by her oncologist three days before her death.

O’Hara, celebrated for her roles in ‘Schitt’s Creek’, ‘Home Alone’, ‘Beetlejuice’ and a long list of comedy classics, had been widely believed to have succumbed to a short illness after an initial statement from her representatives said only that she died “following a brief illness.” The certificate states she was cremated and records her profession simply as “actress,” noting that she had worked in films for half a century.

Final hours and medical background

Additional details released this week reveal that O’Hara began experiencing breathing difficulties at her Brentwood home on the morning of 30 January. She was transported to hospital by the Los Angeles Fire Department in “serious” condition and was pronounced dead shortly afterwards. The death certificate lists the immediate cause as a pulmonary embolism, describing rectal cancer as the secondary condition that contributed to it.

Reports also noted that O’Hara was known to have situs inversus, a rare condition in which internal organs are reversed from their usual positions. While generally harmless, it can create challenges when diagnosing medical problems.

A storied career in comedy and film

O’Hara was born in Toronto in 1954 and emerged from the Second City comedy troupe alongside long-time collaborator Eugene Levy. Her first film, ‘Double Negative’ (1980), featured both Levy and John Candy, setting the stage for a prolific career across sketch comedy, film and television.

She became a global household name in 1990 as the mother of Kevin McCallister in ‘Home Alone’, reprising the role two years later in ‘Home Alone 2: Lost in New York’. Her filmography grew to include Tim Burton’s ‘Beetlejuice’ and ‘The Nightmare Before Christmas’, as well as Christopher Guest’s acclaimed mockumentaries ‘Best in Show’, ‘A Mighty Wind’ and ‘For Your Consideration’.

In recent years, O’Hara reached a new career high as Moira Rose in ‘Schitt’s Creek’, earning an Emmy, a Golden Globe and a SAG Award for the role. She also appeared in ‘The Last of Us’ and Apple TV+’s ‘The Studio’. Her final public appearance was in October 2025 at the Angel Awards in Los Angeles.

O’Hara is survived by her husband, production designer Bo Welch, whom she married in 1992, their sons Matthew and Luke, and her siblings Michael O’Hara, Mary Margaret O’Hara, Maureen Jolley, Marcus O’Hara, Tom O’Hara and Patricia Wallice.

Colleagues including Macaulay Culkin, Eugene Levy, Christopher Guest and Pedro Pascal shared tributes following her death.

What is a Pulmonary Embolism?

A pulmonary embolism occurs when a blood clot or other material lodges in an artery in the lungs, blocking blood flow and reducing oxygen levels. The Cleveland Clinic states that around 900,000 people in the United States experience the condition each year. Without immediate treatment, it can cause long-term damage to the heart or lungs and can be fatal.

According to the Mayo Clinic, common warning signs include sudden shortness of breath, chest pain and fainting. The organisation also lists additional symptoms such as:

  • Coughing up blood
  • Rapid or irregular heartbeat
  • Lightheadedness
  • Excessive sweating
  • Fever
  • Pain or swelling in the lower leg
  • Clammy or discoloured skin

The Mayo Clinic notes that a pulmonary embolism typically forms when a blood clot travels from the deep veins of the legs – a condition known as deep vein thrombosis – although less common causes include fat from fractured bones, tumour fragments or air bubbles.

“About 33% of people with a pulmonary embolism die before they get a diagnosis and treatment,” the clinic warns.

Who is at higher risk?

While anyone can develop the condition, several factors increase the likelihood of a pulmonary embolism, including:

  • A previous history of blood clots
  • Heart disease
  • Certain cancers
  • Surgery
  • Clotting disorders
  • COVID-19
  • Inactivity or prolonged bed rest
  • Long-distance travel
  • Smoking
  • Obesity
  • Use of supplemental oestrogen
  • Pregnancy

Prevention and treatment

Experts emphasise the importance of movement, exercise and compression devices to reduce the risk of clot formation. Individuals at high risk are typically prescribed blood thinners.

Doctors diagnose pulmonary embolisms using blood tests and imaging scans. Treatment can involve anticoagulants, clot-dissolving drugs or medical procedures, depending on the severity of the blockage. 

(With inputs from AP)