What You Should Know About Pulmonary Embolism

Beloved Schitt’s Creek star and acclaimed comedienne Catherine O’Hara passed away on January 30, 2026, at the age of 71. According to a Los Angeles County death certificate, the immediate cause of her death was a pulmonary embolism — a blood clot that blocked an artery in her lungs. Rectal cancer was listed as the underlying cause.

A pulmonary embolism is a medical emergency that occurs when a clot travels through the bloodstream and lodges in the lungs, blocking blood flow and disrupting oxygen delivery. It is one of the more common cardiovascular emergencies, with nearly 900,000 cases in the United States each year.

How Pulmonary Embolism Happens

Most pulmonary embolisms begin as blood clots in the deep veins of the legs, a condition known as deep vein thrombosis (DVT). When a clot breaks free and travels to the lungs, it can rapidly become life-threatening.

Symptoms often start suddenly and may include:

• Shortness of breath
• Chest pain that worsens with deep breathing or coughing
• Rapid heart rate
• Coughing up blood
• Lightheadedness or fainting
• Leg swelling or pain, typically in the calf

In O’Hara’s case, her death certificate indicates she died within hours of the onset of symptoms.

Why Some People Are at Higher Risk

While anyone can develop a pulmonary embolism, certain factors significantly increase risk, including:

• A history of blood clots or clotting disorders
• Recent surgery or long periods of immobility
• Cancer and cancer treatments, which raise the risk of clot formation
• Heart disease
• Smoking and obesity
• Supplemental estrogen use and pregnancy

Cancer patients in particular face a heightened risk. Rectal cancer and other gastrointestinal malignancies are known to increase clotting risk due to factors such as inflammation, reduced mobility, and effects of treatment.

“Without quick treatment, a pulmonary embolism can cause heart or lung damage and even death,” notes the Cleveland Clinic. “About 33% of people with a pulmonary embolism die before they get a diagnosis and treatment.”

Diagnosis and Treatment

Pulmonary embolisms are typically diagnosed using imaging tests such as CT scans or ventilation-perfusion (V/Q) scans, often alongside blood tests that measure clotting markers.

Treatment depends on severity but often includes:

• Anticoagulants (blood thinners) to prevent further clotting
• Thrombolytic therapy to dissolve clots in severe cases
• Compression devices to improve blood flow in the legs
• Lifestyle measures such as staying active and hydrated

Experts emphasize that prompt medical care is essential if symptoms appear.

Prevention Tips

To reduce the risk of pulmonary embolism, especially during long periods of sedentary activity or travel, doctors recommend:

• Staying physically active and walking regularly
• Using compression stockings when recommended
• Elevating legs during long travel or extended sitting
• Staying hydrated
• Working with your healthcare provider to manage underlying conditions such as heart disease or cancer

A pulmonary embolism is treatable and often preventable when risk factors are addressed early.