What is hemoptysis?

What is Hemoptysis?

Hemoptysis is the expectoration of blood from the lung alveoli or airways of the lower respiratory tract, originating from the tracheobronchial tree rather than from nasopharyngeal or gastrointestinal sources. 1

Clinical Definition and Differentiation

• Hemoptysis specifically refers to blood or blood-stained mucus coughed up from the lower respiratory tract, typically originating from bronchial arteries. 2, 3
• This must be distinguished from pseudohemoptysis (blood from nasopharyngeal sources) and hematemesis (blood from gastrointestinal sources). 2
• The blood in true hemoptysis comes from the lung alveoli or conducting airways below the larynx. 1

Classification by Severity

The severity classification is critical because morbidity and mortality correlate more closely with the rate of bleeding than the absolute volume expectorated. 4

Mild Hemoptysis

• Less than 30 mL of blood in 24 hours 4
• Comprises more than 90% of cases and has a good prognosis 2
• Generally does not require bronchoscopic therapy 1

Moderate to Severe Hemoptysis

• 30-300 mL of blood in 24 hours 4

Massive Hemoptysis

• Most commonly defined as greater than 200-400 mL of blood in 24 hours, though some use a threshold as low as 100 mL when there is risk of asphyxiation. 4
• Mortality rate ranges from 59% to 100% in patients with lung cancer 1
• Fatal massive hemoptysis results more commonly from asphyxiation rather than exsanguination, as blood clot formation obstructing the airways is the primary mechanism of respiratory failure. 1
• Requires urgent bronchoscopy for airway protection regardless of exact volume 4

Common Causes

The etiology varies significantly by geographic location and healthcare setting:

In Outpatient Primary Care Settings

• Acute respiratory tract infections (most common) 1
• Chronic obstructive pulmonary disease 1
• Malignancy 1
• Bronchiectasis 1

In Tertiary Referral Centers (North America/Europe)

• Bronchiectasis 1
• Respiratory infections 1
• Lung carcinomas 1

In Developing Countries

• Tuberculosis and its sequelae remain the most prevalent cause 1

Additional Important Causes

• Sarcoidosis 1
• Autoimmune diseases causing capillaritis or cavitation 1
• Coagulopathies 1
• Vascular causes including pulmonary arteriovenous malformations, pulmonary pseudoaneurysms, and pulmonary artery aneurysms 1
• Pulmonary embolus is an uncommon cause despite common clinical concern 1

Cryptogenic Hemoptysis

• Accounts for approximately 20% of patients who undergo extensive investigation with both CT and bronchoscopy without identifying a cause 1
• This is a diagnosis of exclusion after complete workup 5

Clinical Presentation in Malignancy

• Hemoptysis is the presenting symptom in 7% to 10% of patients with lung cancer 1
• More likely with cancers involving the airways (squamous cell carcinoma, small cell carcinoma, carcinoid tumors) than peripheral parenchymal lesions like adenocarcinoma 1
• Cough is present in greater than 65% of lung cancer patients at diagnosis, with productive cough in greater than 25% 1