Marijuana Smoking and Lung Disease

Woman Smoking Joint
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Smoking marijuana is associated with respiratory problems such as chronic obstructive pulmonary disease (COPD) and recurrent lung infections. The effects are dose-dependent—which means that the more marijuana you smoke, the higher your risk of developing respiratory issues.

Additionally, secondhand smoke from marijuana is also associated with adverse health effects, especially among children who are exposed to marijuana in an enclosed or indoor environment.

Respiratory Effects of Smoking Marijuana

The impact of smoking marijuana is similar to the impact of smoking cigarettes on your lungs. You are likely to experience more severe effects if you smoke both marijuana and cigarettes.

Marijuana and COPD

As a consequence of chronically smoking marijuana, you may experience wheezing, a cough, sputum production, and shortness of breath. These symptoms are generally worse with physical exertion—an effect that is often described as exercise intolerance.

Over time, the effects of smoking marijuana can become persistent and severe.

Chronically smoking marijuana is associated with several types of COPD, including:

  • Emphysema: In addition to emphysema (damage of the air sacs in the lungs) marijuana use also increases the risk of a severe type of emphysema—bullous emphysema. Bullae are air pockets that are formed in the lungs due to the breakdown of lung tissue. When these air pockets pop, they can result in a pneumothorax (collapse of the lung,).
  • Bronchitis: Bronchitis is inflammation of the lungs. Marijuana-induced lung damage causes inflammation. Inhalation of marijuana can cause acute bronchitis that lasts for a few days or weeks, or it can cause chronic, long term bronchitis.
  • Bronchiectasis: A disorder characterized by widening of the airways, bronchiectasis can result in a productive cough (coughing up phlegm) and may interefere with your ability to breathe.

Marijuana-induced damage can produce permanent changes in the structure of the lungs—which may cause or exacerbate one or more of types of COPD.

Marijuana and Lung Infections

As a result of chronically smoking marijuana, you can develop a tendency to experience frequent and severe lung infections. You may experience fevers, loss of appetite, and weight loss when you have a lung infection.

The chemicals that you inhale as you smoke marijuana damage the protective cilia in your lungs, making you more vulnerable to getting a lung infection. Additionally, COPD makes you more prone to recurrent lung infections.

Marijuana also inhibits your immune system, predisposing you to lung infections or other types of infections (such as skin infections and ear infections).

Diagnosis of Marijuana-Induced Lung Disease

It can be difficult to know whether your pulmonary symptoms are associated with your marijuana use and whether you have experienced long term damage to your lungs. If you are experiencing symptoms of lung disease, your medical team may order diagnostic tests to help identify the problem.

If you are diagnosed with marijuana-induced lung disease, you may need to begin medical or surgical treatment.

Even if you have not developed respiratory symptoms, some diagnostic tests can identify early-stage lung disease, which can help in guiding your decisions about smoking marijuana.

Pulmonary Function Tests

Typically, pulmonary function tests (PFTs) can be used to assess your respiratory function. These tests can measure your inspiration (breathing in) and expiration (breathing out), as well as the amount of air that your lungs can hold. These values often change as a result of lung diseases.

Your PFTs can be measured with a spirometer—a device that you would use as you inspire and expire based on specific instructions. A spirometer can measure the volume of air that you expire and inspire at timed intervals.

PFT tests include:

Imaging Tests and Lung Biopsy

You may also need to have an x-ray, computerized tomography (CT), or magnetic resonance imaging test (MRI) of your chest and lungs to identify respiratory problems. These tests can show signs of pneumonia (a lung infection) or COPD. They can also be used to help identify the cause of a lung infection that isn't improving with treatment, lung cancer, or a pulmonary condition that has been difficult to diagnose

In some instances, you may need to have a bronchoscopy, which is an interventional imaging test. With this test, your doctor would place a camera into your breathing tubes to visualize your lungs. You may also need a lung biopsy, which is a sample of tissue that is collected surgically so that it can be examined under a microscope.

Medical Marijuana and Pulmonary Disease

At the current time, the use of medicinal marijuana is not thought to be harmful to the lungs. In general, medical marijuana is used in low doses. Typically, medical marijuana is not consumed by smoking and may be used as a prescription pill or liquid.

Many states are now approving medical marijuana for the management of cancer symptoms, especially pain and nausea. The effects of medical marijuana are thought to be beneficial in preventing cachexia (severe weight loss and nutritional deficiency), which is often the direct cause of death in end-stage cancer.

A Word From Verywell

Cigarette smoking is by far the strongest risk factor for the development of COPD. Smoking marijuana is also a strong risk factor for acute lung problems like infections and serious, life-threatening chronic lung diseases.

While smoking cigarettes is a strong risk factor for lung cancer, the link between marijuana and lung cancer is not well established at this time.

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