Haemoptysis: Causes and Risk Factors Behind Coughing Up Blood

The lungs receive blood from two sources, namely the pulmonary and bronchial arteries. The pulmonary arteries, which are supplied by the right ventricle of the heart, carry blood to the alveoli. In contrast, the bronchial arteries, branching off from the aorta, deliver blood to the lung’s supporting structures, including the bronchial tree, hila and pleural viscera. Approximately 90% of haemoptysis cases originate from the bronchial circulation, while around 5% are due to the pulmonary circulation. Other causes may involve systemic bleeding.

The presence of blood when you cough, which is usually characterised by being frothy or foamy with mucus or saliva, is a frequent symptom. The colour of the mucus can go from pink and red to rust, and it is usually just in small quantities.

Classification

Haemoptysis is classified as massive haemoptysis and non-massive haemoptysis.  

Massive haemoptysis is defined as the expectoration of more than 400 millilitres of blood within 24 hours or 150 to 200 millilitres of blood in a single instance.  

Blood expectoration below massive haemoptysis, that is, below 400 millilitres of blood within 24 hours or 150 to 200 millilitres of blood in a single instance, is classified as non-massive haemoptysis.

Haemoptysis vs haematemesis  

Haemoptysis (coughing up blood) and haematemesis (vomiting blood) are often confused, but they are distinct conditions. Haemoptysis, or coughing up blood, typically appears as a blood-streaked spit mixed with mucus and originates from the throat or mouth. It can result from various respiratory issues like infections, inflammation or lung conditions. On the other hand, haematemesis involves expelling a larger volume of blood, usually due to internal bleeding in the upper gastrointestinal (GI) tract.  

Haematemesis can be caused by conditions such as gastric ulcers, varices or gastrointestinal bleeding. While both involve the presence of blood, the key difference lies in the source and amount of blood. If you experience either of these symptoms, it is important to seek medical attention to determine the cause and receive appropriate treatment. Proper diagnosis and prompt care are crucial in addressing both conditions effectively.

Causes  

The haemoptysis causes can vary from mild (the most common) to serious and potentially life-threatening. In most cases, coughing up blood is associated with an infection. The most common haemoptysis causes include:

• Bronchitis
• Pneumonia
• Tuberculosis
• Other haemoptysis causes include:
• Bronchiectasis
• Cystic fibrosis
• Vasculitis
• Drug use (crack/cocaine)
• Lupus complications
• Congestive heart failure
• Using anticoagulants (blood thinners)
• Damage to the arteries in the lungs
• Irritation caused by a bronchoscopy biopsy
• A blood clot in the lungs (pulmonary embolism)
• Chronic obstructive pulmonary disease (COPD)
• Pulmonary aspiration (inhalation of blood into the lungs)
• Lung cancer, particularly in individuals over 40 who smoke
• Blood from the nose, tonsils or teeth entering the throat
• A foreign object or obstruction in the airway (more common in children)

Diagnosis

Your healthcare provider will evaluate your medical history, conduct a physical examination and ask specific questions to identify the cause of your haemoptysis. They may inquire about:

• The quantity of blood you have been coughing up
• The frequency of blood expectoration
• The duration of your symptoms
• The amount of blood mixed with mucus or saliva

Your healthcare provider may also inquire about risk factors, such as smoking or drug use, and will likely ask about any other symptoms you have been experiencing to help identify potential causes.

They may conduct one or more of the following tests to determine the underlying cause:

• Chest X-ray: It is used to detect tumours or fluid accumulation in the lungs.
• Computed tomography (CT) scan: It is used to scan the chest to further investigate X-ray findings or to assist in an additional procedure, such as a bronchoscopy.
• Bronchoscopy: It is used to examine the airways and identify the source of the bleeding.
• Complete blood count (CBC): It is used to evaluate blood loss and detect signs of infection.
• Sputum culture: Here, lung secretions are cultured to identify potential causes of infection, such as bacteria or viruses, that may be contributing to the haemoptysis.
• Coagulation test (blood clotting test): It is used to assess whether a bleeding disorder is contributing to your symptoms.
• Pulmonary arteriography: It is used to evaluate blood flow through the lungs.
• Urinalysis and/or kidney function test: It is used to rule out autoimmune disorders that could affect both the lungs and kidneys.

In addition to the tests mentioned above, your healthcare provider may conduct other procedures based on the suspected cause of your haemoptysis.

Treatment

Haemoptysis treatment will vary based on the severity of your blood loss and the underlying cause of your haemoptysis. If you are experiencing significant blood loss, you will be treated in the intensive care unit (ICU). The medical team will focus on stabilising you and controlling the bleeding before diagnosing the underlying cause.

Treatment for severe blood loss due to haemoptysis may include:

• Bronchoscopy: This is used to remove any clots from your airways that could be contributing to the bleeding.
• Bronchial artery angiography and embolisation: This is used to block blood flow in the vessels responsible for the bleeding.
• Medication: It is used to control bleeding associated with severe blood loss.
• After identifying the cause of your haemoptysis, your healthcare provider will discuss the most appropriate treatment plan to manage both your symptoms and the underlying condition.

Treatment options for conditions that may lead to haemoptysis include:

• Antibiotics: If pneumonia or tuberculosis is the underlying cause of your condition
• Steroids: If inflammation is contributing to your condition
• Surgery and cancer treatments: If a malignant (cancerous) tumour is the cause of your condition

Conclusion

Haemoptysis (coughing up blood) can have various causes. If you are coughing up a large amount of blood, it is important to call for an ambulance immediately. For smaller amounts, it is essential to see your healthcare provider as soon as possible, especially if the cause is unknown. Sometimes, a serious condition like lung cancer can be the cause. As a general rule, early diagnosis of serious conditions improves the chances of effective treatment and a better outlook.