Why blood clots in cancer can cause shortness of breath

A clot that travels to the lungs is called a pulmonary embolism. It can obstruct blood flow in lung blood vessels, so the body may struggle to take up oxygen and the heart has to work harder to move blood through the lungs. Shortness of Breath is a common presentation of Blood Clots in Cancer. Breathlessness may start suddenly or become noticeable with ordinary activity, and it can occur with chest discomfort, a fast heartbeat, coughing, dizziness, or fainting.

Contact your cancer team or a clinician promptly if new breathlessness develops, even if it seems mild. They can assess your symptoms, check oxygen levels and decide whether tests are needed. Keep taking prescribed blood-thinning medicine exactly as directed unless a clinician tells you otherwise. Tell the team about missed doses, bleeding, new leg pain or swelling, and any recent change in treatment or mobility.

Seek emergency help immediately for sudden severe breathlessness, chest pain, coughing up blood, fainting, confusion, blue or grey lips, or a rapid deterioration. Do not drive yourself if you feel faint or severely unwell. These warning signs need urgent assessment because a lung clot can affect breathing and circulation.

Ask whether your symptoms could be related to a lung clot, which tests are appropriate, and what changes should prompt emergency care. If you use a blood thinner, ask how to take it safely and which bleeding symptoms need urgent advice.