Coughing up blood — a symptom known as hemoptysis — can be a sign of several different conditions. Many of these conditions can be serious, and some even life threatening.

One of the conditions in which hemoptysis may appear is a pulmonary embolism, a blood clot in your lung. When these two occur together, it can be a challenge for doctors. The standard treatments for each condition can actually cause the other condition to worsen.

This article will highlight how hemoptysis happens in pulmonary embolism and how doctors treat the two conditions.

Coughing up blood may be a medical emergency

Many conditions can cause you to cough up blood, including chronic conditions like asthma. While not all of these conditions are emergencies, they become emergencies when they progress to coughing up significant amounts of blood.

If you have a chronic lung disease like asthma or COPD, your doctor will give you a list of symptoms or situations that may arise where you need immediate medical attention. Coughing up blood should be on that list.

More importantly, if you don’t have any known lung conditions and start to cough up blood, call emergency services or seek emergency medical care immediately.

A pulmonary embolism (PE) is essentially a blood clot that becomes lodged somewhere in the lungs. These clots usually come from somewhere else (often your leg) and travel to the lungs.

Once lodged in place, these clots can cut off blood flow in your lungs, causing blood to back up behind the clot. The backup results in increased pressure in the vessels on one side of the clot, and a lack of blood flow and oxygen on the other side.

PE can lead to further blood clots, obstructions, and smaller infarcts — or areas where tissue has died from a lack of oxygen. The increased pressure or lack of oxygen can damage your lung tissue, causing bleeding. This can appear as blood in your sputum.

A PE that can cause such high blood pressure in the lungs would need to be very large and high risk (massive). You would likely experience other serious symptoms and could even become unconscious.

There are different degrees of hemoptysis. Mild hemoptysis is when you cough up less than 100 milliliters of blood in 24 hours. Mild hemoptysis goes away on its own in 9 out of 10 cases.

Massive hemoptysis is when you cough up greater than 100 milliliters of blood in 24 hours. This is when the condition is potentially life threatening. In 90% of cases, massive hemoptysis is due to injury or damage to the bronchial artery.

A 2015 case study suggests that people with chronic PE should seek treatment for even mild hemoptysis.

How common is hemoptysis in pulmonary embolism?

Only about 5% to 7% of people with PE experience hemoptysis. Less than 3% of all cases of hemoptysis are due to pulmonary embolism. According to a 2015 French study, there are several more common causes, including:

Since there can be several possible causes of your hemoptysis, your doctor will first need to determine the location of the bleeding. Pinpointing a location can help identify a cause.

Your doctor will usually use imaging like a chest X-ray or computed tomography (CT) scan. With these scans, they should be able to determine the location and severity of the problem.

In addition to diagnostic imaging, your doctor may run other tests to determine the effect of hemoptysis on your overall health. Possible tests include:

Once your doctor has determined the cause and extent of your hemoptysis, they will begin to develop a treatment plan. In the case of PE, treatment options can be more complicated. How doctors treat PE depends on:

  • where the clot is
  • how large the clot is
  • how much damage the clot has already caused

Regardless of the extent or location of the blood clot, immediate medical treatment for PE is critical. The goal of treatment is to either dissolve the clots and keep new ones from forming, or to physically remove or break up the clot and restore blood flow.

The standard treatment for PE is anticoagulation. But when hemoptysis is present, doctors face a dilemma. Anticoagulation can increase your risk of bleeding.

Vena cava filter

In this case, your doctor may opt for a vena cava filter. Your doctor will place this filter in your inferior vena cava, a large blood vessel. Doctors only use a vena cava filter for patients who can’t take anticoagulants.

A vena cava filter won’t treat the clot in your lungs, but it can prevent new clots from traveling to your lungs.

Tranexamic acid

But doctors still need to stop the bleeding. They’ll often use tranexamic acid (TXA) to relieve hemoptysis. In case studies from 2017 and 2021 of patients with both hemoptysis and PE, doctors administered TXA by IV.

Previous studies have raised concerns about TXA leading to blood clots and PE. But a large 2019 Japanese study and a 2021 review found it safe.

Bronchial artery embolization

Doctors may also use bronchial angiography to both locate the source of the bleeding and treat it. This minimally invasive procedure allows them to first view the source, and then treat it using a process called trans-catheter bronchial artery embolization (BAE).

In trans-catheter BAE, doctors thread a small tube through your thigh up to your bronchial artery. Doctors then inject tiny particles through the catheter that clot the vessel to stop the bleeding.

BAE is usually very effective, with studies finding its initial success rate to be between 70% and 99%. But there is a chance that hemoptysis may reoccur. Studies found the recurrence rate to be between 10% and 57%.

Several case studies report successful use of BAE to manage hemoptysis with PE. But some older studies saw mixed results.

A 2019 study found that BAE was a safe and effective way to treat hemoptysis in people with chronic thromboembolic pulmonary hypertension (CTEPH), a complication of PE. But the study was small, and researchers stressed the need for more studies.

Coughing up blood isn’t necessarily a sign of PE, but it can happen. More common signs of PE that could suggest a problem include:

Your recovery from PE will depend almost entirely on the size and location of the clot and how quickly you get medical attention.

Without treatment, about 30% of people who develop PE die, according to 2013 research. About 10% of people who develop severe and sudden PE die almost immediately. However, with proper diagnosis and treatment, the mortality rate for PE drops to about 8%.

According to a 2021 review, the mortality rate for hemoptysis is between 9% and 38%. But the same review found that treatment with tranexamic acid reduced mortality rate, bleeding time, and duration of hospital stay.

A 2017 study looking into symptoms of PE found that hemoptysis was usually linked to massive (high-risk) PE. This means that the presence of hemoptysis indicates that your PE is more severe. According to a landmark study, massive PE has a mortality rate of up to 65%.

Early diagnosis and treatment are key to achieving the best possible outlook.

Coughing or spitting up blood can be a sign of several conditions. It doesn’t always appear with pulmonary embolism. But if PE is the cause of this symptom, you need to get medical attention right away.

Immediate and accurate diagnosis and treatment of PE can significantly improve your chances of survival.