Always take it seriously

Coughing up blood is frightening, and it should always be taken seriously, even when the amount is small.

Telling where the blood has come from is a very common problem. Many patients find it difficult to tell the difference between blood coughed up from the lungs and blood that has flowed back into the throat from a nosebleed or from bleeding gums, and even doctors can get it wrong despite detailed and careful history-taking. In a small number of patients, the exact source of bleeding is found only after several investigations or scopes. The important thing is not to dismiss any form of abnormal bleeding, and to seek medical attention early.

How much is too much

No amount of bleeding from the airways or lungs should be considered normal in most patients. A small group of patients with specific lung diseases, such as bronchiectasis or lung cavities from previous infections, frequently see small amounts of blood in their sputum, and even for them it is difficult to say what amount is safe. These patients should seek medical attention if they develop difficulty breathing, or notice more fresh blood or a larger volume than their usual daily amount.

What causes coughing up blood

The causes range from simple infections to bronchiectasis, tuberculosis, blood clots in the lung and lung cancer. There are no official statistics that we know of on the common causes of haemoptysis in Singapore, but the causes include:

• Infection. Any lung infection, from a simple upper respiratory tract infection to pneumonia or a more serious infection such as tuberculosis, can cause haemoptysis. In most acute infections the bleeding resolves with treatment. Where TB is possible, further evaluation such as sputum tests, CT scans and/or bronchoscopy is needed.
• Lung cancer. Most patients worry about lung cancer when they cough up blood, yet in many cases of lung cancer haemoptysis is absent. Lung cancer cannot be ruled out as the cause from symptoms and examination alone, so most patients need further tests.
• Autoimmune conditions. Rare causes include vasculitis and connective tissue disorders, such as lupus (SLE) and ANCA-related vasculitis, in which the immune system becomes dysregulated. These conditions usually need a multidisciplinary team and carefully coordinated management.
• Heart failure. In some cases heart failure can present with haemoptysis, usually alongside other symptoms of heart failure such as breathlessness and leg swelling.
• Medicines. Blood thinners, both antiplatelet medicines and anticoagulants, can sometimes contribute to haemoptysis. Even so, patients on these medicines need further evaluation to rule out other causes such as infection and cancer.

How we find the source

As with most conditions, a careful history and examination is the first and most important step. A CT scan and blood tests are then needed, and a CT scan and sometimes a bronchoscopy help us find the source. A bronchoscopy is often needed to rule out a growth or tumour within the airways, even when the CT scan does not show one, because lesions inside the airway can be missed on CT and need to be seen directly.

How the bleeding is treated

Most bleeding stops with treatment of the cause, but for heavier or recurrent bleeding, we can block the bleeding vessel with a procedure called bronchial artery embolisation. This is used to stop bleeding from specific causes such as bronchiectasis (chronically damaged airways): a catheter is passed into the artery that supplies the bleeding area of the airway, and coils or gels are placed to block it. It sometimes helps in other causes, such as lung cavities, with varying degrees of success.

Treatment depends on the cause of the bleeding. Bleeding from a tumour, for example, usually does not respond well to bronchial artery embolisation and may need radiotherapy or, in some cases, surgical removal.

What happens afterwards

Patients with a significant amount of bleeding are usually monitored in an intensive care or high-dependency unit. Small amounts of bleeding are usually manageable with conservative treatment, but large amounts can require a patient to be placed on a ventilator. Once discharged, patients need close follow-up to watch for recurrence, which is common.

Related reading

Lung and Respiratory Conditions: A Patient Guide · Chronic Cough: It's Not Just the Lungs · Pulmonary Embolism: Symptoms and Treatment · The Aeden Physicians

Frequently Asked Questions

What are the causes of coughing up blood?

The causes range from simple infections to bronchiectasis, tuberculosis, blood clots in the lung and lung cancer. Rarer causes include autoimmune conditions, heart failure and blood-thinning medicines.

Is coughing up a small amount of blood serious?

Coughing up blood is frightening, and it should always be taken seriously, even when the amount is small. No amount of bleeding from the airways or lungs should be considered normal in most patients.

How is heavy or recurrent bleeding treated?

Most bleeding stops with treatment of the cause. For heavier or recurrent bleeding, we can block the bleeding vessel with a procedure called bronchial artery embolisation; bleeding from a tumour may need radiotherapy or surgery instead.