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. Over time, however, they may experience health issues, such us coughing up blood and having 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.

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

They include:

  • facial swelling
  • fluid around the lungs
  • infections
  • blood clots
  • high calcium levels
  • problems with the nervous system, such as spinal cord compression and neuropathy
  • cardiovascular problems, including blood clots
  • blockages in the airways or food pipe
  • tumors in other parts of the body, due to metastasis
  • mental health problems

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

Facial swelling

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

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

In some cases, it can be the first sign 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 lungs

Excess fluid around lungs, also known as pleural effusion, refers to 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. Other options include reducing the pleural space by introducing irritants into it or placing a catheter.

Higher risk of infection

People with lung cancer have a higher risk of developing lung and other infections.

Reasons include the following:

If a person with lung cancer develops a fever, sore throat, pain, and other signs that may indicate an infection, they should seek medical attention immediately.

A doctor may recommend treatment with antibiotics.

Learn about the links between pneumonia and lung cancer here.


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

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 here.

Blood clots

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

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

Spitting up blood

Blood in mucus or sputum can indicate lung cancer, especially if a person coughs up bright red blood or blood clots. However, this can also occur with tuberculosis or a pulmonary embolism.

If a person produces blood-tinged sputum rather than blood, they may have another respiratory disease, such as bronchitis. If the sputum is also white and frothy, it may be a sign of congestive heart failure.

If a person spits up blood without coughing, they may have damage in the gastrointestinal tract.

According to a 2017 article, 90% of mild cases of coughing or spitting up blood resolve without treatment. Around 17.4% of cases are due to cancer, while 25.8% stem from other respiratory diseases.

Nevertheless, 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 here.


A person with hypercalcemia has high levels of calcium in their blood. Up to 10–30% of people with cancer have hypercalcemia. Lung cancer is one of the cancer types most likely to cause it.

It happens for various reasons. One 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.

It is one of the later signs of cancer. Most people with cancer-related hypercalcemia will not live longer than 1 more year, according to experts.

Learn more about hypercalcemia and its effects here.

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 cardiovascular system.

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

Spinal cord compression

Around 3–5% of people with metastatic cancer experience spinal cord compression. Lung cancer is one type of cancer with which it is most likely to occur.

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

Early symptoms, such as edema, are reversible.

If neurological symptoms persist for more than 48 hours, however, the impact may be permanent.

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

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

Blocked airways or food pipe

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

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

If a person has a tumor near the food pipe, they may experience pain as food passes to the stomach.

Receiving a lung cancer diagnosis can severely affect a person’s mental health. It can increase the risk of depression and suicide, research shows.

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 seek guidance from a healthcare professional.

According to research, lung cancer can have a more serious impact on people who already have a severe mental health condition. It is essential to get advice from a doctor and seek appropriate support from mental healthcare professionals if a person has both conditions.

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:

  • increased risk of blood clots
  • bone problems
  • difficulty thinking and functioning, known as brain fog
  • mouth and dental problems
  • diarrhea
  • fatigue
  • hair loss
  • nausea and vomiting
  • neuropathy
  • pain
  • rash
  • changes in weight
  • edema
  • higher risk of infection

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 here.

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 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 illness that can be fatal. However, current medical practice means many people are living longer than before since receiving a diagnosis.

Non-small-cell lung cancer is the most common type. People who receive a diagnosis in the early stages have a 63% chance of living 5 years or longer, compared with a person who does not have the disease. For SCLC, the chance is 27%.

Complications can result from both the cancer and the treatment. Some are temporary, but others will 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.