Symptoms
The main symptom of dyspnea is labored breathing. The degree of shortness of breath can vary, with some people experiencing it with physical activity and others experiencing it chronically.
Some people describe the shortness of breath they experience with lung cancer as “not being able to catch their breath,” “being unable to get enough air,” and “feeling like they’re being smothered or suffocated.”
Other symptoms can co-occur with dyspnea and help describe the severity of the symptom. These include:
Tachypnea: Abnormally rapid breathing (generally more than 20 breaths per minute in an adult) Cyanosis: A bluish discoloration of the lips, mouth, or fingers due to the lack of oxygen Pallor: Pale skin caused by reduced blood flow and oxygen Nasal flaring: When the nostrils widen while breathing Chest retractions: When the skin between the ribs sinks in while inhaling
Causes
The severity and duration of dyspnea can vary by the underlying cause. With lung cancer, there are many possibilities.
Since some of the causes associated with lung cancer are treatable, it is important to tell your oncologist about any shortness of breath you experience—even if it is relatively minor.
All possible causes should be explored during the diagnosis. If not, you may be given drugs that relieve the symptom but mask the true underlying cause. In some cases, shortness of breath may be an early sign of a serious condition.
Tumor Progression
One of the more common reasons for increased shortness of breath is growth of the tumor inside the lung. This is because airflow can be obstructed when a tumor grows in or near one of the large airways.
The displacement of functional tissue with malignant tissue will almost invariably reduce lung function—often minimally with early-stage cancer but more significantly as the disease progresses.
Reduced Lung Volume
Surgery for lung cancer, such as a lobectomy, pneumonectomy, or wedge resection, results in reduced lung volume and increased difficulty with breathing, especially during activity.
Scarring after surgery and prolonged radiation therapy can also reduce functional lung volume and lead to chronic shortness of breath.
Pleural Effusion
With pleural effusion, excessive bodily fluids build up between the membranes that line the lung, called the pleura. This can compress the lungs, reducing the amount of oxygen that reaches the small air sacs of the lung (the alveoli). The fluid can be benign or contain cancer cells, the latter of which is referred to as malignant pleural effusion.
Pericardial Effusion
Fluid can also build up between the membranes that line the heart and lead to pericardial effusion. The pressure created can compress the heart, reducing the volume of blood that is pumped through the body and, in turn, the amount of oxygen supplied to tissues.
Lung Infections
Lung infections such as pneumonia are common with lung cancer, and shortness of breath is sometimes the only clue that a lower respiratory infection is developing.
Pneumonia commonly occurs when a tumor partially obstructs the airways, but can also be the result of immunosuppression caused by chemotherapy. The body is simply less able to fight common bacterial or viral infections that target the lower respiratory tract because of changes to the immune system.
Radiation Pneumonitis
Radiation pneumonitis is a common side effect of radiation therapy for lung cancer. Exposure to radiation can lead to generalized inflammation of the lungs, causing airways to narrow and secrete excess mucus. Shortness of breath is a common related feature.
It is important to treat radiation pneumonitis aggressively since it can progress to pulmonary fibrosis, in which the tissues of the lungs become permanently scarred. This can lead to chronic shortness of breath and overall diminished lung function.
Pulmonary Embolism
People with lung cancer, especially lung adenocarcinoma, have a significantly increased risk of developing blood clots in their legs (venous thrombosis). These clots can then break off and travel to the lungs, causing a pulmonary embolism.
Symptoms of pulmonary embolism may initially be mild but gradually progress. It can also develop dramatically with severe and sudden shortness of breath and chest pain. Pain, swelling, redness, and/or tenderness of the calves are also commonly noted.
Because pulmonary emboli are common in people with advanced lung cancer, lifelong treatment with blood thinners may be required.
Anemia
Anemia is a condition in which you lack enough functional red blood cells to carry adequate oxygen to the body’s tissues. It may be caused by chemotherapy, other cancer treatments, or the malignancy itself (referred to as anemia of chronic disease).
Shortness of breath is a common feature of anemia, particularly when it is severe. Anemia is readily treatable, even in the more advanced stages of lung cancer.
Drug Allergy
Many of the medications used to treat lung cancer can cause allergic reactions. Although drug hypersensitivity can occur with most chemotherapy drugs, it is more common with L-asparaginase, Taxol (paclitaxel), Taxotere (docetaxel), Vumon (teniposide), Matulane (procarbazine), and Cytosar (cytarabine).
A drug allergy may be mild, causing itching, mild diffuse rash, and mild shortness of breath. But it can also develop rapidly and lead to a potentially life-threatening condition known as anaphylaxis.
Anxiety
It is not uncommon to experience anxiety with lung cancer, which can not only manifest with restlessness, irritability, and insomnia, but also physical symptoms such as rapid heart rate and shortness of breath.
Anxiety can amplify the sensation of breathlessness and vice versa. Anxiety can often be treated with anxiolytic drugs or counseling.
Associated Medical Conditions
People with lung cancer often have other chronic medical conditions such as chronic obstructive pulmonary disease (COPD), congestive heart failure, asthma, and hypothyroidism. Shortness of breath is common with all of these disorders and may require different treatments to be controlled.
Obesity can also exacerbate shortness of breath when pressure from the abdomen restricts the amount of air that can be drawn into the lungs.
Diagnosis
If you have increased shortness of breath, there are a number of lab tests and imaging studies your healthcare provider may order.
Lab Tests
The first step usually involves pulse oximetry to check your oxygen saturation levels. Arterial blood gases (ABG) can measure the acidity (pH) and levels of oxygen and carbon dioxide in a sample of blood. This information offers insight on how well oxygen is being delivered and carbon dioxide is being removed from tissues.
A complete blood count (CBC) can help determine if you have anemia, an infection, or an inflammatory reaction, providing clues as to the underlying cause.
Imaging Studies
Your healthcare provider will also likely order an imaging test like a chest X-ray or computed tomography (CT) scan to see if there is any evidence of obstruction, pneumonia, or effusion.
If the progression of cancer is suspected, magnetic resonance imaging (MRI) with contrast or a positron emission tomography (PET) scan may be ordered. MRIs are especially useful in imaging soft tissue, including smaller tumors. PET scans can detect metabolic changes that occur when cancer progresses and can often spot metastases (the spread of cancer) that other imaging techniques cannot.
Suspected pulmonary embolisms can be diagnosed with another imaging technique called a ventilation-perfusion (VQ) scan.
If the healthcare provider suspects a tumor is obstructing an airway, a bronchoscopy may be performed. This involves the insertion of a flexible scope into the airways to directly view tissues.
Grading Dyspnea
When referring to shortness of breath, it’s important to distinguish the subjective sensation of not getting enough air from the physical signs of impaired respiration. The two are often related, but not always.
The sensation of breathlessness doesn’t necessarily reflect the oxygen saturation in the blood or the amount of oxygen being delivered to tissues.
Healthcare providers can get a clearer idea of the level of care needed based on how a person responds to dyspnea. Someone who gets short of breath after walking a few feet, for instance, would be treated differently than someone who gets dyspnea after walking a few blocks.
Understanding the degree of dyspnea ensures that the best care is delivered. The assessment can be made a system called the mMRC Dyspnea Scale which grades shortness of breath by the following subjective criteria:
Grade 0: Dyspnea only occurs with strenuous exercise. Grade 1: Dyspnea occurs with walking up a hill or when hurrying on level ground. Grade 2: On level ground, a person walks slower than someone else of the same age or must stop to catch their breath in this setting. Grade 3: A person must stop to catch their breath after walking the equivalent of 100 yards on flat ground or after a few minutes of walking. Grade 4: A person is unable to leave home due to shortness of breath or becomes short of breath with normal activities, such as dressing,
Treatment
The treatment of dyspnea is focused on reducing shortness of breath, managing anxiety, and treating the underlying cause.
If your symptoms are mild, your oncologist or primary care physician may be able to manage or treat your symptoms. Chronic dyspnea related to advanced lung cancer usually benefits from palliative care teams that focus on managing symptoms and improving the quality of life for those living with cancer.
Medications
Opioid medications such as morphine not only relax the airways and improve breathing but can help relieve anxiety. People with severe or chronic anxiety may benefit from anxiolytic drugs like Ativan (lorazepam), Valium (diazepam), and Klonopin (clonazepam) to reduce the sensation of shortness of breath.
People with chronic dyspnea related to advanced lung cancer will sometimes be prescribed a short-acting bronchodilator like albuterol to help improve breathing. The drug is inhaled when needed and is most often prescribed when lung cancer is accompanied by an obstructive airway disease like COPD.
Airway Obstruction Resolution
When a lung tumor grows into the airway, it can cause shortness of breath as well as increase the risk of infection and bleeding. Sometimes a stent will need to be placed to bypass the obstruction.
Radiation therapy can be very effective at treating cancer at the site of an obstruction, providing rapid relief of respiratory symptoms in people receiving palliative care.
Effusion Management
It is not uncommon for a few liters of fluid to accumulate in people with severe pleural effusion. This can be treated with a procedure called a thoracentesis in which a long, thin needle is inserted through the chest wall to drain fluid from the pleural cavity.
Because recurrence is common, a stent may be placed in the chest wall with an external outlet so that fluids can be drained at home when needed. In other cases, a procedure known as pleurodesis may be used to bond tissues in the pleural cavity together so that fluids have no space to accumulate.
Pericardial effusions are managed in a similar way. Treatment options include pericardiocentesis, in which fluid is withdrawn from the pericardial cavity. Stenting may also be used as well as a surgical procedure called a pericardiectomy that removes some or all of the membrane surrounding the heart.
Oxygen Therapy
Oxygen therapy, either continuous or intermittent, may be needed if your oxygen saturation is low.
Portable oxygen therapy has improved dramatically over the last few decades, and many people can live active lives despite the regular need for oxygen. For those who have COPD and lung cancer, oxygen therapy may improve survival.
Pulmonary Rehabilitation
If shortness of breath is related to surgery or radiation therapy, your healthcare provider may recommend pulmonary rehabilitation as an option. Pulmonary rehabilitation is a relatively recent therapeutic approach that can help manage your breathing problems, increase stamina, and decrease breathlessness.
Among its facets, pulmonary rehabilitation typically involves resistance exercises to build strength in the respiratory muscles and breathing exercises to increase oxygen levels and decrease the sensation of breathlessness.
Coping
In addition to medical treatments, there are a number of simple things people can do to better cope with the feeling of breathlessness that can stem from lung cancer.
Breathe Fresh Air
It is fairly obvious that people with dyspnea should avoid smoking or secondhand smoke. But there are other air quality issues that can impact your breathing both in and out of the home.
If you live in an urban area and have an air quality alert, stay indoors. Shut all windows and doors, and use an air conditioner to regulate air temperature. If you need to go outdoors, wear a face mask.
Indoor air quality can be improved by using an air purifier, ideally one that has dual HEPA and charcoal-activated filters. The best air purifiers can remove 99% of airborne pollutants as small as 0.3 microns in size.
Avoid air fresheners, perfumes, and noxious fumes from household cleaners, paint, or varnish.
Prevent Infection
Infections such as the flu and pneumonia can worsen shortness of breath. Reduce your risk with careful handwashing, by avoiding crowds (especially during the flu season), and making sure that you are up-to-date on your flu and pneumonia vaccinations.
People with lung cancer need to be extra vigilant as their immune function may be significantly impaired by chemotherapy.
Exercise
Routine mild to moderate exercise can be beneficial to improving your lung function and reducing shortness of breath. Aerobic exercise is especially helpful as it strengthens the heart and improves oxygen capacity. Examples include walking, dancing, or any activity that increases your heart rate.
Food and Drink
Staying well-hydrated can help reduce the build-up of mucus in the airways, especially if you are using oxygen. Some people find that dairy products can worsen their shortness of breath due to the thickening of mucosal secretions. Eating a smaller meal several times a day and taking small bites can also be beneficial.
Sleeping
Many people find that their shortness of breath increases when lying flat. Sleeping at a 45-degree angle may help. Instead of struggling with normal pillows, use a wedge pillow to prop you up securely. Sleeping in a cool room can also improve breathing.
Breathing Techniques
Breathing exercises can be very helpful, especially if you also have COPD. Many people with dyspnea find that pursed-lip breathing (in which you inhale slowly and deeply through the nose and exhale slowly and fully through pursed lips) not only decreases breathlessness but gradually increases lung capacity.
Diaphragmatic breathing, also known as belly breathing, can also increase the amount of air entering the lung while reducing stress and anxiety.
Stress Reduction
Stress clearly intensifies the sensation of breathlessness and can interfere with your well-being in other ways. Relaxation exercises, such as progressive muscle relaxation, controlled breathing, meditation, and visualization, can help control anxiety if performed consistently. Music therapy and gentle yoga classes are also offered by many cancer treatment centers for this purpose.
Sometimes, very simple measures can change your emotional outlook, such as consciously pacing your day to avoid breathlessness or sitting near a window if you feel claustrophobic. Even a walk outdoors can lift your spirits by exposing you to sunlight and fresh air while generating mood-lifting endorphins.
A Word From Verywell
Dyspnea can be distressing and debilitating, adding to the challenges of living with lung cancer. It is important to remember, however, that the sensation of breathlessness can be exacerbated by how you react to it emotionally.
As important as it is to get the appropriate medical treatment for dyspnea and its underlying cause, you may also benefit from exercise, stress management, counseling, and building a strong support network of family, friends, and health providers. Over the long term, this can help you better cope with the physical and emotional challenges of living with lung cancer.
