Multiple myeloma is a type of cancer that affects a specific part of your body’s immune system called plasma cells. To explain it simply: What Are Plasma Cells? Plasma cells are a kind of white blood cell found in your bone marrow, which is the soft, spongy tissue inside your bones. These cells are part of your immune system and help protect you from infections by making antibodies, which are proteins that fight off germs. What Happens in Multiple Myeloma? In multiple myeloma, these plasma cells start growing out of control. Instead of making healthy antibodies, they multiply too much and produce abnormal proteins that can’t fight infections properly. This overcrowding in the bone marrow can also prevent your body from making enough healthy blood cells. Symptoms of Multiple Myeloma Bone Pain: Because multiple myeloma affects the bones, it often causes pain, especially in the back, ribs, or hips. Weakness and Fatigue: You might feel very tired or we...