You are currently viewing What to know about pneumonia and lung cancer

What to know about pneumonia and lung cancer

Lung cancer and pneumonia also arise in the lungs and have many similar symptoms. Lung cancer, too, can increase pneumonia risk by weakening the immune system.

Pneumonia is a lung infection that leads to trouble breathing and lung fluid. The pneumonia may be caused by various viruses, bacteria , and fungi.

Lung cancer arises as a result of overgrowth of lung cells, which may form tumors. Lung cancer is the second most common form of cancer in the United States, and the leading cause of death from cancer, according to the American Cancer Society ( ACS).

In this article we look at the link between pneumonia and lung cancer and their effects on the body.

What is the link?

Old man coughing
Coughing is a symptom of both pneumonia and lung cancer.

Lung cancer rarely causes symptoms until its later stages. Yet pneumonia may develop as a lung cancer complication.

Individuals with a weakened immune system are especially vulnerable to developing pneumonia. For this reason, 50–70% of people with lung cancer develop serious infections of the lung during their illness, such as pneumonia.

In fact, the aggressive treatments used by physicians to treat lung cancer also significantly impair immune function. That means people may be less able to prevent the entry of infectious agents into their bodies. They may also have more difficulty fighting infections and may not respond well to medicines.

Infections pose a significant health risk for these individuals. Infection is actually the second most common cause of death in people with lung cancer outside of the tumors.

A weaker immune system also accounts for the significant impact that pneumonia has on very young people and older adults.

More information on lung cancer can be found here.

Differences in symptoms

Lung cancer is not always symptom inducing. When it does, however, they usually occur when the cancer has entered an advanced stage.

Many signs of the lung cancer and pneumonia overlap. Usually pneumonia symptoms are more severe immediately. By general, lung cancer progresses more gradually and does not cause symptoms until it reaches an advanced stage.

Overlapping symptoms include:

  • Coughing: This tends to be more persistent in people with lung cancer. It will usually last for several weeks and get progressively worse.
  • Phlegm: This is generally dark red, brown, yellow, or green.
  • Shortness of breath: This is more persistent in people with lung cancer than those with pneumonia. However, people with pneumonia experience more acute breathlessness that may progress more quickly without treatment.
  • Stabbing chest pains: These get worse during a breath or a cough.
  • Tiredness: People with lung cancer commonly feel more fatigue than those with pneumonia.
  • Loss of appetite: People with lung cancer tend to experience loss of appetite, which may result in weight loss.
  • Wheezing: This is rare in both lung cancer and pneumonia.

Other symptoms include:

  • fever
  • rapid heartbeat
  • hot and cold flushes
  • headaches
  • nausea or vomiting
  • joint or muscle aches
  • confusion
  • coughing up blood
  • higher
  • persistent chest infections

A doctor does not necessarily use specific signs to differentiate between pneumonia and lung cancer. They should be more focused on how rapidly symptoms progress and the timing of their onset.

Lung cancer symptoms

Shoulder pain in ladies
A person with lung cancer may experience shoulder pain.

Common symptoms that occur only in people with lung cancer include:

Less common symptoms include:

  • swelling in the face or neck
  • long lasting shoulder or neck pain
  • difficulty swallowing
  • hoarseness
  • changes in the shape of the fingertips

Find out more about lung cancer here.

Risk factors

Any individual can develop pneumonia as well as lung cancer. Nonetheless, other factors make certain health problems more likely to occur.

Another risk factor for pneumonia is lung cancer itself. Receiving chemotherapy for lung cancer treatment can also increase a person’s risk of pneumonia by reducing immune function.

Smoking tobacco is an significant risk factor for developing lung cancer , especially over an extended period of time. It also contributes to the risk of developing pneumonia.

Other risk factors for lung cancer include:

  • exposure to carcinogenic chemicals, such as radon, asbestos, and uranium
  • a family history of lung cancer
  • previous radiation therapy to the chest
  • air pollution, which some researchers suggest is responsible for 5% of global lung cancer deaths

The following factors can increase the risk of pneumonia:

  • chronic lung diseases, such as chronic obstructive pulmonary disease (COPD) or cystic fibrosis (CF)
  • chronic illnesses in other parts of the body, such as diabetes and heart disease
  • a repressed immune system, which may occur due to chemotherapy treatment for cancer, HIV, organ transplants, or using steroid medications over a long period
  • recent respiratory infection with a virus, such as flu
  • staying in a hospital, especially when using a ventilator
  • drug and alcohol abuse, which can increase the risk of a specific type known as aspiration pneumonia

Want to quit smoking? Learn more here.

Diagnosis and treatment

A female doctor in office with patient
To diagnose pneumonia, a doctor may carry out a physical examination.

A doctor can perform a physical exam when diagnosing pneumonia to check for swollen glands, excessive respiration or high temperature.

The diagnosis is also confirmed by a doctor using an X-ray to demonstrate fluid build-up in the lungs.

Treatment can vary depending on a person ‘s form of pneumonia, and overall health. Some people at home can treat pneumonia with plenty of fluids, medication and rest.

Patients with more serious pneumonia can need to stay at hospital to receive fluids and antibiotics intravenous (IV). They can need oxygen therapy or breathing aid, too.

A doctor has greater difficulty in diagnosing lung cancer. An X-ray in the chest may provide some information, but to confirm the diagnosis, a biopsy is often required.

If a doctor confirms a lung cancer diagnosis, they will ask for more testing, including a PET scan. It will help them determine the extent to which the cancer has spread.

Often, they’ll order a biopsy. A specialist takes a small sample of the tissue and sends it under a microscope for analysis.

A doctor usually extends a tiny tube through the nose or mouth into the lungs to extract the sample. Typically, they’ll use a CT scan to guide the biopsy.

The outcomes of these tests will determine the type of lung cancer, where the primary tumor is located, and the stage of the disease.

The doctor will use this knowledge to assess the most appropriate treatment plan, as well as the individual’s general health.

Treatments are intended to treat, monitor or relieve symptoms. Based on the extent of the lung cancer, the treatments available will vary from simple surgical procedures to chemotherapy or radiotherapy.


The majority of pneumonia cases are not extreme, although the illness is dangerous.

The duration of symptoms depends on the person ‘s overall health and the type of pneumonia they have.

It can take several weeks for pneumonia to heal. Vital organs, such as the heart and brain, may not get enough oxygen without treatment. This can result in confusion, coma, heart failure or death.

Whatever the treatment, the outlook for lung cancer tends to be worse than pneumonia. If pneumonia is left untreated, however, this can lead to death.

Early diagnosis of lung cancer raises the risk of the tumors being surgically removed before they spread. That gives an person a good chance of recovery.

According to the American Lung Association, however, only 16 percent of people with lung cancer are treated before it spreads.

If the cancer spreads or metastasizes to remote organs in the body, it is less than 5 percent likely to live for 5 years. According to the American Lung Association, over half of all people with this type of cancer don’t survive for more than a year.

Chukwuebuka Martins

Chukwuebuka Martins is a writer, researcher, and health enthusiast who specializes in human physiology. He takes great pleasure in penning informative articles on many aspects of physical wellness, which he then thoroughly enjoys sharing to the general public.