What Is Mesothelioma? Symptoms, Causes and Prevention

Medically Reviewed by Nancy A. Nelson, MPH

Photo Courtesy: FatCamera/iStock

Mesothelioma is a rare type of cancer that affects the lining of your chest and abdomen. You get it by breathing in or swallowing asbestos — a type of microscopic mineral that can cause cancer when it gets inside your body.

Mesothelioma symptoms are similar to symptoms of lung cancer and other conditions, so it can be hard to get the right diagnosis. There are some treatments, but unfortunately, about nine out of ten people with mesothelioma die within five years. That’s why it’s so important to prevent this cancer by avoiding asbestos.

Learn about mesothelioma and how to protect yourself.

What Are the Types of Mesothelioma?

The most common types of mesothelioma are:

  • Pleural mesothelioma — in the lining of the chest wall
  • Peritoneal mesothelioma — in the lining of the abdomen (belly area)

Less often, mesothelioma affects the tissue surrounding the heart or testicles.

What Are the Symptoms of Mesothelioma?

Symptoms of mesothelioma in the chest area include:

  • Shortness of breath or difficulty breathing
  • Trouble swallowing
  • Hoarseness
  • Cough
  • Pain in the rib cage area
  • Lumps under the skin of the chest
  • Swelling of the face and arms

Symptoms of mesothelioma in the abdomen include:

  • Abdominal pain or swelling
  • Constipation
  • Nausea

Both kinds of mesothelioma can also cause: 

  • Fatigue
  • Weight loss
  • Loss of appetite

If you notice these symptoms, talk with your doctor to find out what’s causing them.

What Causes Mesothelioma?

You can only get mesothelioma by breathing in or swallowing asbestos (or in rare cases, other types of fine dust). Asbestos is a natural mineral that crumbles into long, thin fibers that are easy to breathe in. It takes a long time for asbestos to cause mesothelioma after it gets into your body — often 20 years or more.

When you breathe in asbestos, the fibers move into your lungs and gather there. If they stay inside your lungs, they can cause lung cancer or a chronic lung disease called asbestosis. 

Sometimes the fibers poke through the lung tissue and escape into the area surrounding the lungs. They land on the lining of the chest and gather there over the years. When too many fibers gather, they overwhelm your body’s immune defenses and form mesothelioma tumors in the chest lining.

Sometimes after people breathe in asbestos fibers, they cough them up and swallow them. After you swallow the fibers, they can move through the walls of your intestines and into the space around them. When too many fibers gather in that space, they can form tumors on the intestinal lining in your abdomen.

How Do You Come in Contact with Asbestos?

Asbestos can work as an insulator, so some industries use it to make products that protect against heat and fire. Most people who get mesothelioma work (or used to work) in industries that use asbestos, like:

  • Asbestos mining and milling
  • Shipbuilding
  • Oil refining
  • Pipefitting and plumbing
  • Insulation work
  • Manufacturing products with asbestos in them

Scientists discovered how dangerous asbestos was in the 1970s, and now the U.S. government regulates workplace asbestos levels. Some workers in jobs like construction and demolition may still come in contact with it, but it’s much less common today.

You can also come in contact with asbestos through non-work activities, like:

  • Washing clothes with asbestos fibers on them
  • Repairing car brakes (brakes may contain asbestos)
  • Doing home repairs involving insulation, flooring, wall treatments and tiling (these materials sometimes contain asbestos)

Am I at Risk?

If you’ve spent time in a setting with asbestos fibers in the air, you may be at risk for mesothelioma. It can take 20 years or longer to develop — and because most asbestos exposures happened in work settings decades ago, it’s most commonly diagnosed in older men.

You’re also at higher risk if you have family members with this cancer, or if you’ve had multiple chest x-rays. Living with someone exposed to asbestos at work or at home can increase your risk of second-hand exposure to asbestos.

Even if you’ve come in contact with asbestos, that doesn’t mean that you’ll get mesothelioma. Only a small number of people who are exposed to asbestos go on to develop this cancer. 

But it’s important to know that asbestos can also cause more common diseases, including other lung conditions and other cancers. If you think you’ve been around asbestos at work or at home, talk with your doctor about your health risks.

How Can I Prevent Mesothelioma?

The only way to prevent this cancer is to limit your exposure to asbestos. If you work in a setting with asbestos, make sure to follow all your workplace’s health and safety procedures — like wearing protective gear.

At home, avoid activities that might expose you to asbestos, like repairing brake linings on your car or doing home renovations that involve materials with asbestos. If your home was built before 1980 and you’re planning renovations, have it tested for asbestos before you start.

How Will My Doctor Diagnose Mesothelioma?

To make a diagnosis, your doctor will start with a basic physical exam and ask you questions about your symptoms and health history. They’ll also ask about your work exposures to asbestos and other kinds of dust. 

Then your doctor will use tests to see if you have mesothelioma tumors and find out more about the tumors. Tests may include:

  • Chest x-rays
  • Biopsies (taking small samples of tissue to look at under a microscope)
  • Scans (like CT or MRI scans) to take detailed images of your internal organs

If your doctor tells you you have mesothelioma, the next step will be to find out what stage the cancer is. Stages depend on the tumor’s size, how far it’s spread and whether surgery can remove it.

What Are the Treatments for Mesothelioma?

Once it develops, mesothelioma is fast-moving — so it’s important to get treatment right away. Treatment depends on your age, your overall health and how far the cancer has spread. Your doctor may recommend:

  • Surgery to remove the tumors
  • Radiation therapy
  • Chemotherapy
  • Immunotherapy to increase your body’s own defenses against cancer cells
  • Monoclonal antibody therapy or other treatments that target specific cancer cells

These treatments aren’t always effective. That’s why it’s so important to prevent this cancer by avoiding contact with asbestos. If you’re concerned about asbestos at your home or workplace, talk with your doctor about ways to protect yourself.