When a person has lung cancer, tumors develop in the lungs. In time, they can spread to other parts of the body, and various complications can arise, such as facial swelling, blood clots, and infections.

Many people with lung cancer do not notice any signs or symptoms in the early stages. However, over time they may experience health issues. For example, they may cough up blood or have swelling due to a buildup of fluid.

This article looks at some of the common complications of lung cancer and lung cancer treatment, as well as some ways of managing them.

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As lung cancer develops, a range of complications can occur.

They include:

  • blockages in the airways, leading to breathing problems
  • blockage in the food pipe, which can make it hard to swallow
  • spitting or coughing up blood or rust-colored sputum
  • facial swelling
  • fluid around the lungs
  • infections
  • tumors in other parts of the body due to metastasis
  • blood clots
  • heart and cardiovascular problems
  • high calcium levels
  • problems with the nervous system, such as spinal cord compression and neuropathy
  • mental health conditions

Below, we look at each of these in more detail.

Blocked airways

A tumor may grow into an airway in the lung and block it. This may lead to further complications, such as pneumonia and shortness of breath.

Blocked food pipe

Lung cancers that grow near a person’s esophagus, or food pipe, can cause complications, making it painful or difficult for a person to swallow.

Spitting up blood

Blood in mucus or sputum can indicate lung cancer. However, this can also occur with tuberculosis, a pulmonary embolism, congestive heart failure, or intestinal damage.

According to a 2017 research review, 17.4% of cases of coughing up blood are due to cancer, while 25.8% stem from other respiratory diseases.

Any production of blood, whether through spitting or coughing, needs urgent medical attention. It may or may not be a sign of cancer, but a doctor can make a correct diagnosis.

Learn more about the causes of blood in sputum.

Facial swelling

Facial swelling can sometimes be a complication of lung cancer. It can occur when tumors in the lungs block the flow of blood in a blood vessel known as the superior vena cava. Healthcare professionals refer to this as superior vena cava syndrome (SVCS).

Cancer is a common cause of SVCS, and most cases are due to lung cancer or non-Hodgkin lymphoma. SVCS may worsen when a person is lying down or raising both arms. Other symptoms of SVCS include:

In some cases, SVCS can be the first sign of cancer that appears.

A 2018 case study describes the experience of one person who approached a dermatologist about swelling around the eyes and a feeling of swelling in the face and throat. Diagnostic tests showed that the person had small-cell lung cancer (SCLC).

Excess fluid around the lungs

Excess fluid around the lungs, or pleural effusion, is a buildup of fluid between the membranes that cover the lungs. The fluid can then press against the lungs, causing breathlessness.

In some cases, a doctor can drain the excess fluid to relieve symptoms. Alternatively, a doctor may reduce the pleural space by introducing irritants into it or by placing a catheter.

Higher risk of infection

Some 35–70% of deaths among people with lung cancer are due to infections.

This can happen because cancer compromises lung health, increasing the risk of bronchitis or pneumonia. Some types of treatment also reduce the effectiveness of the immune system.

If a person with lung cancer develops a fever, a sore throat, pain, or other symptoms of an infection, they should seek medical attention immediately.

A doctor may recommend treatment with antibiotics.

Learn about the links between pneumonia and lung cancer.


As cancer progresses, it spreads to other parts of the body. Cancer cells can move from the lungs to the liver, the bones, the brain, and other areas through the lymphatic system or bloodstream.

Possible symptoms include:

  • bone pain if cancer affects the bones
  • headache, dizziness, and seizures if it spreads to the brain
  • yellowing of the eyes (jaundice) if it spreads to the liver
  • swelling of the lymph nodes in the neck or above the collarbone

In the later stages, cancer may affect many parts of the body, but it will still be lung cancer if it began in the lungs.

Learn more about metastatic lung cancer.

Blood clots

The American Cancer Society notes that people with cancer — especially lung cancer — may have a higher risk of blood clots. When cancer spreads to other parts of the body during metastasis, this can increase the risk as well.

Experts do not know exactly why this happens, but it may stem from tissue damage that occurs with cancer.

Heart and cardiovascular problems

Around 23% of people with lung cancer have cardiovascular disease. One reason may be that smoking is a strong risk factor for both diseases.

Even if a person does not already have heart disease, lung cancer can affect the heart and the cardiovascular system.

Lung cancer can also increase the risk of blood clots, which may lead to heart problems.


A person with hypercalcemia has high levels of calcium in their blood. This often occurs with metastatic lung cancer and other types of cancer.

A doctor may diagnose hypercalcemia when levels are as follows:

One reason is that the bloodstream reabsorbs calcium from the bones when cancer damages them. Changes to the hormonal system can also contribute.

Symptoms of hypercalcemia include fatigue, confusion, constipation, and nausea.

Learn more about hypercalcemia and its effects.

Spinal cord compression

Up to 5% of people with metastatic cancer experience spinal cord compression. Lung cancer is one of the types of cancer in which this is most likely to occur.

Metastatic spinal cord compression can happen when a vertebra collapses due to damage from cancer or when a tumor develops and presses on the spinal cord.

Anyone who experiences limb weakness, numbness, difficulty walking, a loss of bowel or bladder control, or pain in the chest or spine should contact their doctor.


Neuropathy is numbness and tingling in the hands and feet due to damaged nerve tissue. It can be a complication of lung cancer.

Neuropathy can occur when tumors are growing near the nerves in the arm or shoulder. A tumor compresses the nerves, leading to pain and weakness.

Receiving a lung cancer diagnosis can severely affect a person’s mental health. It can increase the risk of depression and suicide, according to a 2018 study.

Anyone with a diagnosis of lung cancer who experiences signs of depression, such as sleep problems, a low mood, and weight changes unrelated to the diagnosis, should consider speaking with a health professional.

Suicide prevention

If you know someone at immediate risk of self-harm, suicide, or hurting another person:

  • Ask the tough question: “Are you considering suicide?”
  • Listen to the person without judgment.
  • Call 911 or the local emergency number, or text TALK to 741741 to communicate with a trained crisis counselor.
  • Stay with the person until professional help arrives.
  • Try to remove any weapons, medications, or other potentially harmful objects if it’s safe to do so.

If you or someone you know is having thoughts of suicide, a prevention hotline can help. The 988 Suicide and Crisis Lifeline is available 24 hours a day at 988. During a crisis, people who are hard of hearing can use their preferred relay service or dial 711 then 988.

Find more links and local resources.

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Treatment for lung cancer involves chemotherapy, radiation therapy, and targeted drug therapy. A person may also have surgery.

Each treatment will have different side effects, but common problems include:

  • difficulty thinking and functioning, known as brain fog
  • problems with the mouth and teeth
  • diarrhea
  • fatigue
  • hair loss
  • nausea and vomiting
  • neuropathy
  • pain
  • rash
  • changes in weight
  • higher risk of infection
  • blood clots after surgery

Some of these effects can resemble the symptoms and complications of cancer, and it is not always easy to tell them apart.

Learn more about some common side effects of chemotherapy.

Treatment can provide relief from many of the complications that occur with lung cancer. This may include:

  • using medication to help manage pain and neuropathy
  • draining fluid from around the lungs or heart
  • opening the airway with a stent
  • removing tumors that block the airway

It is not always possible to prevent the complications of lung cancer, but some tips may help a person slow the progress of the disease and live more comfortably.

They include:

  • getting regular exercise, if possible
  • eating regular healthy meals
  • staying in touch with friends and family
  • joining a support group
  • finding out as much as possible about the condition
  • getting enough rest
  • finding things a person can do and enjoys doing
  • learning some breathing exercises for when breathing is difficult
  • following the treatment plan in terms of medication, appointments, and follow-up
  • using palliative care, such as pain relief, to manage symptoms

A doctor can advise on steps to take, depending on which stage of cancer a person has.

Lung cancer is a serious disease that can be fatal. However, current treatments enable many people to live longer after receiving a diagnosis than they might have in the past.

Non-small cell lung cancer is the most common type. People who receive a diagnosis in the early stages have a 65% chance of living 5 years or longer, compared with a person who does not have the disease. For SCLC, the chance is 30%.

Here are some questions people often ask about lung cancer complications.

What are the complications of lung cancer?

The complications of lung cancer include breathing difficulty, fluid around the lungs, and a higher risk of infections, blood clots, and neuropathy. Tumors and other symptoms may appear if cancer spreads. Living with cancer can also affect a person’s mental health.

What are the complications of lung cancer treatment?

The complications of treatment will depend on the treatment a person receives but may include a higher risk of blood clots and bone problems. Side effects may include nausea and vomiting, hair loss, and fatigue.

What happens when lung cancer gets worse?

As lung cancer progresses, a person may find it harder to breathe. They may also have a higher risk of blood clots, infections, and other health concerns. If the cancer spreads to the liver, for instance, they may notice a yellowing of the whites of the eyes due to jaundice. If the cancer affects the brain, they may experience confusion, among other symptoms.

Complications can result from both lung cancer and its treatment. Possible complications include a higher risk of infections, blood clots, and mental health conditions. Some are temporary, but others may last or worsen over time. Some complications can be life threatening.

There are ways of managing complications and helping a person maximize their quality of life. A doctor can advise on ways to manage each type of complication.