Shortness of Breath in Breast Cancer: How Common, Why It Happens, and What Helps

Shortness of breath (dyspnea) can occur with breast cancer, and it is more often seen when the disease is advanced or has spread. ^[1] It may range from breathlessness during activity to trouble breathing even at rest, and it should be promptly discussed with your care team because it can be treated. ^[2]

How Common Is It?

Shortness of breath isn’t usually an early symptom of breast cancer confined to the breast, but it can become relatively common when cancer spreads to the chest, lungs, or when treatment or complications affect the heart or lung function. ^[1] It is also a recognized symptom near the end of life in people with cancer, with multiple possible causes that can be managed for comfort. ^[2]

Main Causes

• Pleural effusion (fluid around the lungs): Fluid can collect between the lung and chest wall due to cancer, making it harder for the lungs to expand and causing breathlessness. [PM15] This complication is especially associated with lung and breast cancers and typically presents with dyspnea. [PM15]
• Lung involvement (metastases or lymphangitic spread): Cancer cells in the lungs or spread along lung lymph vessels can impair gas exchange and cause progressive shortness of breath. [PM18] Lack of relief after fluid drainage may suggest causes like trapped lung or lymphangitic carcinomatosis. [PM18]
• Pulmonary embolism or tumor microemboli: Blood clots or microscopic tumor emboli in lung vessels can cause sudden or worsening breathlessness and can be life‑threatening. [PM16]
• Pericardial effusion (fluid around the heart): Fluid around the heart can lead to chest pressure and breathlessness; drainage may be required to stabilize symptoms. [PM14]
• Treatment‑related lung effects: Certain therapies (for example, trastuzumab) have been linked to pulmonary events such as dyspnea, pleural effusions, and pulmonary edema, often in the context of infusion reactions. ^[3]
• Deconditioning and anemia: Advanced cancer and its treatments can reduce fitness and blood oxygen‑carrying capacity, leading to exertional dyspnea. ^[4]

When to Seek Urgent Care

Sudden, severe shortness of breath, chest pain, fast or irregular heartbeat, dizziness, trouble speaking, or vision changes could signal emergencies such as blood clots or cardiac complications and warrant immediate medical attention. ^{[4] [5]}

How It’s Evaluated

Your team may assess symptoms, perform a physical exam of the chest and lymph nodes, and order imaging (ultrasound, chest X‑ray, or CT) to look for fluid, lung changes, or clots; pleural fluid sampling may be done to confirm malignant effusion and exclude infection. ^[1] [PM15] Ultrasound at the bedside can quickly identify pleural fluid and guide safe drainage when needed. [PM17]

Evidence‑Based Management

Management focuses on treating the underlying cause and relieving distress so you can breathe more comfortably. [PM15]

• Drain fluid (thoracentesis): Removing pleural fluid often gives rapid relief; if fluid keeps returning, options include repeat drainage, an indwelling pleural catheter for home management, or pleurodesis to prevent re‑accumulation. [PM15] [PM18]
• Pleurodesis (talc or other agents): Seals the pleural space to reduce recurrent effusions; talc pleurodesis has among the highest success rates when appropriate. [PM18]
• Indwelling pleural catheter: A flexible tube allows regular fluid drainage at home and is effective for ongoing symptom control, especially when pleurodesis isn’t suitable. [PM18]
• Treat pericardial effusion: Pericardiocentesis (drainage) can stabilize breathing and circulation; in selected cases, instillation therapy may help prevent fluid recurrence. [PM14]
• Manage clots or tumor emboli: If pulmonary embolism is suspected, clinicians may use anticoagulation; tumor microemboli are rare and require specialized care. [PM16]
• Cancer‑directed therapy: Systemic treatments may shrink metastases and reduce effusions; regimens are tailored to tumor type and prior therapies, with monitoring for lung adverse events. ^[3]
• Palliative dyspnea care: Oxygen if hypoxemic, low‑dose opioids for the sensation of breathlessness, anti‑anxiety strategies, cool airflow (fan), positioning, and pacing activities can meaningfully ease symptoms. ^[6] Practical tips such as using a fan, practicing breathing techniques, and seeking timely help when symptoms worsen are part of supportive care. ^[7]

Practical Tips You Can Try Now

• Use a small fan to direct cool air to your face, practice pursed‑lip breathing, and sit upright with supported arms to reduce the work of breathing. ^[6]
• Pace activities and take rest breaks; keep a symptom diary to share with your team. ^[6]
• Ask about oxygen if your oxygen level is low, and discuss medications that can safely reduce the sensation of dyspnea. ^[6]
• Contact your care team promptly if breathlessness is not controlled, or if you feel chest heaviness, palpitations, or new dizziness. ^[4]

What to Expect

Shortness of breath can be different for everyone only during exertion for some, continuous for others and multiple causes may overlap; your care team can tailor investigation and treatment to your situation. ^[2] With appropriate interventions like draining fluid, optimizing cancer therapy, and using supportive measures many people experience meaningful relief and improved quality of life. [PM15] [PM18]

---