Many people will experience a nagging cough at some point in their life. However, a persistent cough, or coughing blood, can be symptoms of lung cancer.

Coughing helps the lungs clear potential germs and harmful objects out of the airway.

A cough that lingers for weeks or even months could indicate something serious. Sometimes, it is due to lung cancer.

This article looks at the link between coughing and lung cancer, when to contact a doctor, and what treatment options are available.

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There are numerous reasons for a cough, and many of them are not serious and will resolve on their own.

However, while a cough does not typically mean that lung cancer is present, a persistent cough is a common symptom of lung cancer at the time of diagnosis. A 2020 study of people with lung cancer found that 54% of participants not undergoing treatment had a cough, compared with 40% in treatment.

How to tell if a cough is lung cancer

There is no way to diagnose lung cancer based on lung cancer symptoms alone, and certainly not based solely on the presence of a cough. A 2019 study of people with lung cancer found that the severity of the cough did not correlate with the severity of the disease.

However, some characteristics of a cough are linked to the risk of lung cancer, including:

  • a persistent cough that does not go away, or that gets worse over time
  • coughing up blood or brown or red mucous
  • cough in a person with a history of smoking
  • frequent respiratory infections such as pneumonia and bronchitis
  • cough associated with wheezing or shortness of breath
  • a cough that produces lots of thin mucous

Conversely, normal coughs typically:

  • appear in response to an irritant, such as smoke or something in the throat
  • occur as part of a short-term illness that goes away
  • may or may not produce mucus, but do not normally produce large quantities of blood or dark mucous

A cough that sticks around for no apparent reason, or an illness that does not resolve, may warn of lung cancer.

Avoiding or quitting smoking can reduce the risk of many conditions that involve a cough, including lung cancer.

A persistent or worsening cough is not the only symptom of lung cancer. Other symptoms of this condition include:

Chronic obstructive pulmonary disease (COPD) is another serious condition that often affects people who smoke.

Learn more about the link between COPD and lung cancer here.

There are many reasons for a cough. For example, a short-term cough could be a result of:

  • an infection, such as a cold or pneumonia
  • an allergy, such as hay fever
  • inhaled dust, smoke, or debris
  • irritation in the throat from food
  • a dry throat from dehydration

The following can also lead to a persistent or chronic cough:

Learn more about the causes of a dry cough here.

Most coughs will subside or disappear within 3–8 weeks.

However, it is important to seek guidance from a doctor if a cough lasts for a long time or occurs alongside other symptoms, such as coughing up blood.

The doctor can determine the cause of the cough and provide appropriate treatment if necessary.

Not everyone with lung cancer will have a cough. For instance, Pancoast tumors develop at the top of the lung and do not cause a cough.

Diagnosis

When assessing a person with a persistent cough, doctors may first ask about:

  • family and personal medical history
  • how long the cough has lasted
  • what type of cough it is
  • when it is most likely to occur
  • any other symptoms

They will also carry out a physical examination. They will listen to the person’s heart and lungs and look for other possible causes of the cough, such as signs of an infection or postnasal drip.

Depending on the findings, the doctor may order additional tests, such as:

  • Imaging tests: These include a chest X-ray, a CT scan, and an MRI scan.
  • Blood tests: Doctors will often take a complete blood count and assess other cancer markers in the blood.
  • Sputum test: The person may have to provide sputum samples.
  • Biopsy: Medical professionals may take tissue samples by inserting a needle into accessible tumors.
  • Bronchoscopy: In this test, a healthcare professional inserts a small tube down the nose and into the lungs. The same tool can take a small sample of tissue for analysis.

A specialist called a pathologist will look at any cell samples under the microscope to see whether cancer is present and, if so, what type of cancer it is.

Some types of cancer are more aggressive than others. This will affect the outlook and treatment. If the diagnosis is lung cancer, a specialist team will conduct further tests to see how far it has spread.

Learn more about the different types of cancer here.

Sometimes, a doctor may also suggest genetic testing.

Genetic features can vary between cancer types. Some newer drugs target specific features that encourage cancer to grow. Knowing what features are present may enable a doctor to suggest a genetic treatment targeting that type of cancer more effectively than conventional treatments.

If a person receives a lung cancer diagnosis, the doctor will talk with them about a treatment plan.

These plans vary from person to person. The doctor will consider the type of cancer and the person’s age and overall health, among other factors.

Treatment options include:

  • Surgery: If the cancer is limited, a surgeon can remove part of the lung. They may also remove nearby lymph nodes.
  • Radiation therapy: A machine targets the malignant cells with a beam. This can kill cancer cells to either shrink a tumor before surgery or remove any remaining cells after surgery.
  • Chemotherapy: This can kill cancer cells, but it can also have severe adverse effects on healthy cells.
  • Targeted therapy: These drugs target specific genes, proteins, and other factors that contribute to cancer development. They aim to stop or delay cancer growth.

Some lifestyle changes may also help improve the outlook, even after a diagnosis. These include:

If the cancer has spread significantly, it may no longer be possible to remove or cure it. The doctor may recommend palliative care, including radiation therapy, to prevent further complications and treat any symptoms.

Management and self-care strategies

Living with lung cancer, regardless of the type of cancer, can be difficult. These strategies may help:

  • Embrace a healthy lifestyle that includes moderate exercise, healthy eating, and stress management. This may help a person feel better and reduce the risk of additional symptoms.
  • Discuss the risks and benefits of treatment with a doctor. Some treatments prolong life but do not cure cancer and may make a person feel very sick.
  • Ask a doctor about medications for fatigue. Many people with lung cancer struggle with fatigue and may not find relief from self-care strategies alone.
  • Talk to loved ones about final wishes and end-of-life care preferences. For example, would a person prefer aggressive treatment that means they die in a hospital, or palliative care and hospice?
  • Ask a doctor about life expectancy, so a person can plan and get their affairs in order.
  • Consider joining a support group for practical wisdom from other people living with cancer.
  • Tell loved ones what would be most helpful. Friends and family may want to offer support, but may be unsure what to do.
  • Talk to a doctor about symptoms, including side effects of cancer treatment. Often, medications or lifestyle changes can reduce the severity of these symptoms.
  • Speak with a therapist who specializes in serious and terminal illnesses. Talking through emotions, weighing options, and nonjudgmental support can make living with cancer feel less overwhelming.

The outlook for lung cancer depends on various factors, such as the:

Early stage cancer is easier to treat and likelier to have a positive outcome than later stage cancer.

For people with non-small-cell lung cancer, the chance of living for at least 5 y ears after diagnosis is:

  • 63% when the cancer is localized, which means that it is still in the original location
  • 35% if it is regional, having spread to nearby tissues
  • 7% if it has spread to more distant parts of the body
  • 25% overall

For small-cell lung cancer, the average 5-year survival rates are:

  • 27% for localized cancer
  • 16% if it has spread to nearby lymph nodes
  • 3% if it has reached distant parts of the body
  • 7% overall

Anyone with a persistent cough that occurs alongside chest pain, shortness of breath, or bloody spit should consult a doctor. If lung cancer is present, the outlook will be better if a person seeks help immediately. This means the cancer will have less time to spread.

Lung cancer can develop without an apparent cause. However, exposure to certain substances and some lifestyle habits can increase a person’s risk of developing lung cancer.

One of the most important methods of prevention is to avoid smoking and exposure to secondhand cigarette smoke. One study estimates that smoking tobacco may cause up to 90% of all lung cancer cases.

People can reduce their risk of developing lung cancer by avoiding other carcinogens, such as asbestos. Carcinogens are chemicals that can make cells more likely to become cancerous.

Eating a healthy diet, reaching or maintaining a moderate body weight, and getting regular exercise may also reduce a person’s risk of lung cancer.

Most coughs happen because of minor infections or irritants and resolve on their own within a few weeks.

While having a cough does not always mean a person has lung cancer, a persistent cough is a common symptom of the condition. It may also signal other serious conditions, such as a persistent infection or COPD.

If a person experiences a persistent cough alongside other lung cancer symptoms, such as blood in the spit and chest pain, they should contact a doctor immediately. Early diagnosis and treatment can improve the outlook for people with lung cancer.

There are also a number of ways in which people can reduce their likelihood of developing lung cancer. These include quitting smoking, avoiding exposure to other carcinogens, and exercising regularly.