Cancer starts when cells change (mutate) and grow out of control. The changed (abnormal) cells often grow to form a lump or mass called a tumor. Cancer cells can also grow into (invade) nearby areas. And they can spread to other parts of the body. This is called metastasis.

Multiple myeloma is cancer that starts in plasma cells in your bone marrow. Plasma cells are part of your immune system. They normally make proteins called antibodies (immunoglobulins) that help fight infections. The bone marrow is the soft, inner part of some bones where all the different blood cells are made.

With multiple myeloma, the abnormal plasma cells grow out of control. These cells are called myeloma cells. They collect in the bone marrow and crowd out normal blood cells. They can form tumors in the bones called plasmacytomas. They damage and make the bone weak.

Some people have only one bone tumor. This is called a solitary or isolated plasmacytoma. More often, people have tumors in many different bones. This is multiple myeloma.

A risk factor is anything that may increase your chance of having a disease. The exact cause of someone's cancer may not be known. But risk factors can make it more likely for a person to have cancer. Some risk factors may not be in your control. But others may be things you can change.

The risk factors for multiple myeloma include:

• Being over age 65
• Being African American
• Being a man
• Family history of multiple myeloma
• Exposure to high levels of radiation
• Exposure to certain chemicals, such as benzene and some pesticides
• Obesity
• A history of plasma cell diseases

Talk with your doctor about your risk factors for multiple myeloma and what you can do about them.

There's no sure way to prevent multiple myeloma. But some risk factors can be controlled to help reduce your risk. For instance, limit exposure to and protect yourself from chemicals, and stay at a healthy weight.

There are currently no regular screening tests for multiple myeloma. Screening tests are done to check for disease in people who don't have symptoms.

Multiple myeloma often does not cause symptoms at first. When it does cause symptoms, they depend on where the tumor is or the problems it causes.

Myeloma cells can build up in the bone marrow and crowd out healthy cells. This can cause:

• Weakness, tiredness, or shortness of breath from having too few red blood cells (anemia)
• Frequent infections from having an immune system that has become weak due to fewer white blood cells (leukopenia)
• Easy bleeding or bruising from a low platelet count (thrombocytopenia)

Myeloma cells make a lot of antibodies (M proteins) that make your blood very thick. (This is called hyperviscosity.) While rare, this can cause:

• Dizziness
• Confusion
• Stroke-like symptoms, such as weakness on one side and slurred speech
• Kidney damage

Myeloma in the bone can cause:

• Bone pain (often the back, hips, or skull)
• Breaks (fractures) in the affected bone
• Numbness or weakness in your feet or legs, if the tumor affects the bones in your spine

Myeloma can also cause bone damage. This leads to having way too much calcium in your blood (hypercalcemia). Too much calcium can cause:

• Feeling very thirsty
• Urinating a lot
• Constipation
• Belly pain
• Drowsiness
• Confusion
• Loss of appetite
• Weakness
• Nausea and vomiting

Many of these may be caused by other health problems. But it's important to see a doctor if you have these symptoms. Only a doctor can tell if you have cancer.

Multiple myeloma may be diagnosed when you see your doctor because of symptoms. Sometimes it's only found after abnormal blood or urine tests that were done for another reason, like a routine physical.

Your doctor will ask you about your health history, symptoms, risk factors, and family history of disease. A physical exam will be done.

You may also have one or more of these tests:

• Blood tests
• Urine tests
• X-rays
• Bone marrow aspiration and biopsy

After a diagnosis of multiple myeloma, you'll likely need more tests. These help your doctor learn more about the cancer. Imaging scans are used to see where and how much cancer there is in your body. Tests are also done to find out the stage of the cancer. The stage of multiple myeloma is a measure of certain proteins in your blood and gene changes in the cancer cells. It's one of the most important things to know when deciding how to treat the cancer.

Once your cancer is staged, your doctor will talk with you about what the stage means for your treatment. Be sure to ask your doctor to explain the details of your cancer to you in a way you can understand.

Your treatment choices depend on the number of plasmacytomas you have, where they are, your symptoms, test results, and the stage of the cancer. The goal of treatment may be to control the cancer or help ease problems caused by cancer. Talk with your health care team about your treatment choices, the goals of treatment, and what the risks and side effects may be.

Types of treatment for cancer are either local or systemic. Local treatments remove, destroy, or control cancer cells in one area. Surgery and radiation are local treatments. Systemic treatment is used to destroy or control cancer cells that may have traveled around your body. When taken by pill or injection, chemotherapy and targeted therapy are systemic treatments. You may have one treatment or a combination of treatments.

Multiple myeloma may be treated with:

• Active surveillance
• Chemotherapy (chemo)
• Targeted therapy
• Immunotherapy
• Radiation therapy
• Stem cell transplant

Talk with your doctors about your treatment choices. Make a list of questions. Think about the benefits and possible side effects of each choice. Talk about your concerns with your doctor before making a decision.

Cancer treatments for myeloma, such as chemo and radiation, can damage normal cells. This can cause side effects like hair loss, mouth sores, and vomiting. Other side effects include nerve damage, low blood counts, fatigue, and possibly rashes.

Talk with your doctor about side effects linked to your treatment. There are often ways to manage them. There may be things you can do and medicines you can take to help prevent or control many treatment side effects.

Many people feel worried, depressed, and stressed when dealing with cancer. Getting treatment for cancer can be hard on your mind and body. Keep talking with your health care team about problems or concerns you have. Work together to ease the effect of cancer and its symptoms on your daily life.

Here are tips:

• Talk with your family or friends.
• Ask your health care team or social worker for help.
• Speak with a counselor.
• Talk with a spiritual advisor, such as a minister or rabbi.
• Ask your health care team about medicines for depression or anxiety.
• Keep socially active.
• Join a cancer support group in person or online.

Cancer treatment is also hard on the body. To help yourself stay healthier, try to:

• Eat a healthy diet, with a focus on high-protein foods.
• Drink plenty of water, fruit juices, and other liquids.
• Keep physically active.
• Rest as much as needed.
• Talk with your health care team about ways to manage treatment side effects.
• Take your medicines as directed by your team.

Your doctor will talk with you about when to call. You may be told to call if any of the following occur:

• New symptoms or symptoms that get worse
• Signs of an infection, such as a fever
• Side effects of treatment that affect your daily function or don't get better with treatment

Ask your doctor what signs to watch for, and when to call. Know how to get help after office hours and on weekends and holidays.

• Multiple myeloma is cancer that starts in plasma cells in your bone marrow. Plasma cells are part of your immune system.
• With multiple myeloma, tumors can form in the bones. They damage and make the bone weak.
• Some people have no symptoms. Others have symptoms that will depend on where the tumor is. These can include bone pain, weakness, shortage of breath, urinating a lot, and dizziness.
• Risk factors include being over age 65, being African American, being a man, being obese, and exposure to certain chemicals.
• Treatment may include active surveillance, chemotherapy, radiation therapy, targeted therapy, and stem cell transplant.

Tips to help you get the most from a visit to your doctor:

• Know the reason for your visit and what you want to happen.
• Before your visit, write down questions you want answered.
• Bring someone with you to help you ask questions and remember what your doctor tells you.
• At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your doctor gives you.
• Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.
• Ask if your condition can be treated in other ways.
• Know why a test or procedure is recommended and what the results could mean.
• Know what to expect if you do not take the medicine or have the test or procedure.
• If you have a follow-up appointment, write down the date, time, and purpose for that visit.
• Know how you can contact your doctor if you have questions, especially after office hours or on weekends and holidays.