By Lynne Eldridge, MD 

Updated on June 26, 2023

 Medically reviewed by Gagandeep Brar, MD

 Fact checked by Sarah Scott

More than 80% of people with lung cancer die within five years of diagnosis—and more than half within the first year.¹

American Lung Association. Lung cancer fact sheet.

 Lung cancer causes death in a few different ways. Tumors can grow and spread so much that organs can no longer function. The cancer can also lead to fatal infections or blood clots.²³

If you or a loved one has lung cancer, understanding what end-stage disease is can help you prepare for end-of-life care and address any fears you have, like worrying that death will be painful.

This article will go over the different causes of death in people who have lung cancer, as well as offer some insight into what you can expect during the process of dying from lung cancer. 

KatarzynaBialasiewicz / Getty Images

Causes of Death From Lung Cancer

Research on the specific causes of death related to lung cancer is limited. However, one study looked at over 40,000 small cell lung cancer patients to get an idea of what the most frequent causes of death were.⁴

Research has found that the most common causes of death are:⁵⁶⁷⁸

• The size and spread of tumors or cancer cells (tumor burden)

• Infections

• Problems in other areas where tumors have spread (metastatic complications)

• Pulmonary hemorrhage

• Pulmonary embolism

• Diffuse alveolar damage

• Other complications

Since then, researchers have concluded that for a lot of lung cancer patients, more than one factor ultimately contributes to death.⁹

Tumor Burden

A 2015 study found that tumor burden which refers to the number of cancer cells, the size of the tumor(s) or the amount of cancer in the body overall was predictive of survival rates in patients with lung adenocarcinoma.
¹⁰

In these cases, the tumors in the lungs and other places in the body grew so big that the organs shut down and a person dies.¹⁰

 How Fast Does Lung Cancer Spread?

Infections

Infections remain a leading cause of death among cancer patients in general including those with lung cancer. Pneumonia, tuberculosis and sepsis are the among the most common.¹¹

Complications of Metastatic Disease

In stage 4 lung cancer, cancer cells have spread to other parts of the body. Sometimes, the tumors shut down an organ. Other times, cancer interferes with the normal functioning of those organs and causes other complications.

In one 2015 study, metastatic complications were a factor in the deaths of 77% of patients suffering from cancer of the lung or trachea.¹²

These complications cause death in very different ways. For example, lung cancer that spreads to the brain can affect a person's ability to walk, talk, and swallow, or cause a hemorrhagic stroke.¹³

Once lung cancer is in the nervous system, it can get inside the cerebrospinal fluid—a condition called leptomeningeal metastases. At this stage, the disease is terminal.¹⁴

Lung cancer that spreads to the liver can interfere with the organ's ability to remove toxins from the body, which can cause them to build up and lead to death.¹⁵

Lung cancer can sometimes spread to the membrane around the heart (pericardium) and cause bleeding. The blood causes compression of the organ and sudden, rapid—although painless—death.¹⁶

Pulmonary Hemorrhage

Pulmonary hemorrhage, or bleeding into the lungs occurs in 20% of lung cancer patients to some degree and can be fatal.¹⁷

Coughing up blood is the main symptom of a pulmonary hemorrhage. Even though about one-fifth of people with lung cancer cough up blood at some point in the course of the disease, that does not mean you should ignore the symptom or treat it as something "expected."¹⁷

Even a small amount of bleeding in the lungs can be a medical emergency. In smaller amounts, blood in the lungs can produce a feeling of suffocation. When massive bleeding occurs, however, death is usually rapid.¹⁸

 Which Lung Cancer Symptoms Require Emergency Care?

Pulmonary Embolism

Blood clots in the legs, also called deep venous thrombosis (DVT), can break off and travel to the lungs (pulmonary emboli). A pulmonary embolism causes breathing difficulties, severe pain, and low blood pressure, and may lead to death.¹⁹

Research consistently finds a high prevalence of pulmoarny embolii in patients with certain kinds of cancer including lung.²⁰

Blood clots can happen any time after a diagnosis and are sometimes the first symptom of lung cancer. They are common in people with lung adenocarcinoma and other types of lung cancer with a pooled incidence of 3.7%.
²¹

However, blood clots are sometimes preventable and often treatable. Understanding your risk factors can help you avoid them.

Diffuse Alveolar Damage

Alveoli are the sacs in the lung where oxygen and carbon dioxide are exchanged. Infection and inflammation can damage these balloon-like structures and cause respiratory distress leading to failure and death.
²²

Other Possible Causes of Death From Lung Cancer

• Chemotherapy: These medications cause a low white blood cell count, which can make you more vulnerable to serious, possibly fatal, infections.²³

• Radiation therapy: In some instances, you can get radiation pneumonitis (RP), an inflammation of the lungs from radiation therapy. In fewer than 2% of cases, this complication can be fatal.²⁴

• Complications of surgery: Reactions to anesthesia, bleeding, and other complications can lead to unexpected deaths in people with cancer.²⁵

• Medical errors: It's estimated that medical errors are the third leading cause of death in the United States.²⁶ Anyone under a healthcare provider's care could be at risk for errors. Staying informed and involved in your treatment can help you avoid these problems.

• Other medical conditions. In addition to lung cancer complications, you might also be at risk for other diseases and disorders. Heart disease, including heart attack and blockage, is one of the most common (though unrelated) problems that cancer patients face.²⁷

Why Knowing Can Be Helpful

Learning what is known about the possible future of your disease course can help you identify steps you can take now to prevent or manage such risks and, hopefully, avoid an early death.

For example, if you know about the potential for and risks associated with blood clots, you can be on the lookout for symptoms and signs that mean you need medical care.

Knowing about the risks of dying from advanced stages of lung cancer can improve your overall quality of life up until that point. Even if the causes cannot be treated, you can often be treated for any symptoms you're having.

Understanding how people can die from lung cancer helps you and your loved ones make a plan for how you want to proceed with your care. For example, you may choose to stop cancer treatment or start having palliative care.

Knowing what to expect can also help those close to you assist with your needs. By learning about what might be to come, you won't have to deal with as many unknowns.

Am I Emotionally Ready?

While information about end-of-life care and risks does help some people feel a sense of control and peace, not everyone is ready or able to confront reality—and that's normal, too.

Before you start talking about death and end-of-life care with your provider and loved ones, make sure that you're emotionally prepared. If you think you are but discover that what they say is more than you can handle, it can be helpful to talk with a counselor about how you're feeling.

It's also important to be aware of how people around you are feeling. Before you share information with family members who will be caregivers, people you know who also have cancer, or anyone else—make sure that they really want all the facts upfront. Respect what each person can handle talking about and when they are ready to do so.

Will Dying From Lung Cancer Hurt?

One of the biggest fears of people living with cancer and the people who care for them is that they will be in pain at the end of life.

Sometimes, when a person asks "How will I die?" what they really want to know is, "Will dying be painful?"

The reality is, some people do experience severe discomfort at the end of life. Treatments such as chemotherapy and radiation can be used to relieve some types of cancer pain. In addition, your provider may recommend seeing a pain management specialist to help you during this time.

That said, no one needs to die in pain. Talk to your provider about your symptoms and make sure that your loved ones providing your care know about your needs and wishes at the end of life, and can ensure that they are being met.

 Pain Control at the End of Life

Preparing for End of Life

You may eventually need to confront the question of what the end stages of lung cancer will be like.

This can be a terrifying time, but there are steps you can take that will help it feel less frightening and be a more physically, emotionally, and spiritually peaceful process.

The timeline for end-stage lung cancer varies greatly depending on the type of cancer and any other health problems you have. There are ways to prepare for some aspects of final care no matter what your circumstances are.²⁸

One of the decisions you should be prepared to make is setting a point when it will be time to move from palliative care to hospice care.

While the two terms are sometimes used interchangeably, there are differences in where and how you are taken care of. Make sure that you and your loved ones understand these differences and are clear about what you want.

 What Can You Expect During End Stage Lung Cancer

What Loved Ones Should Know

When talking about death, many people start feeling grief that’s like the grief they would feel after an actual loss. This is called anticipatory grief.

Grieving before death is normal and allows families to come together and heal from past hurts as well as form memories that will live on. You might be coping with feelings of grief even while your loved one is still alive.

Consider talking to a counselor or support group to navigate your feelings and needs. Remember to take time to care for and nurture yourself physically and emotionally, especially if you are a caretaker.

It's also important to understand that people often know they will die soon. Your loved one may speak of seeing or talking to other loved ones who have died.

You may feel unsettled and want to avoid these conversations, but try to engage in them as much as you can. Research has shown that communication at the end of life is as important for loved ones as much as the person who is dying.²⁹

Summary

There are several factors that contribute to dying from lung cancer, including other medical problems like blood clots, infections, and the toll of cancer treatment on the body. If you or a loved one has lung cancer, there are steps you can take to prepare physically and emotionally for death. You can turn to your treatment team and the important people in your life for support.