Multiple myeloma staging systems use blood test results and, in some systems, genetic findings from the myeloma cells to estimate prognosis, also known as outlook. A higher stage generally means a less favorable outlook. But stage does not directly show how quickly myeloma is growing.
Staging terms
The International Staging System (ISS) and the Revised International Staging System (R-ISS) use stages 1 through 3. The Second Revision of the International Staging System (R2-ISS) uses stages 1 through 4.
Staging tests
ISS staging uses the levels of blood proteins beta-2-microglobulin and albumin. These levels help the care team place multiple myeloma into groups with different outlooks. In general, a higher beta-2-microglobulin level and a lower albumin level are associated with a less favorable outlook.
R-ISS also uses the level of lactate dehydrogenase (LDH) and certain chromosome changes in the myeloma cells. A test called fluorescence in situ hybridization (FISH) can find genetic changes.
Stage 1
In R-ISS, stage 1 means the beta-2-microglobulin level is below 3.5 milligrams per liter (mg/L) and the albumin level is at or above 3.5 grams per deciliter (g/dL). The LDH level is within the expected range. The myeloma cells don't have high-risk chromosome changes.
Stage 2
Stage 2 is when test results don't meet all the criteria for stage 1 or stage 3.
Stage 3
Stage 3 means the beta-2-microglobulin level is at or above 5.5 mg/L. The LDH level is also above the expected range, or the myeloma cells have high-risk chromosome changes.
Stage 4
R-ISS doesn't have a stage 4. In R2-ISS, there are four stages, and stage 4 is the highest risk group.
Multiple myeloma also can be given a risk level. Your care team evaluates risk features, such as certain chromosome or genetic changes in the myeloma cells. Stage and risk level are related but give different information to help estimate the prognosis of your condition.
Your healthcare team uses the multiple myeloma stage and risk level to understand your prognosis and plan your treatment.
Symptoms don't follow one fixed pattern for each stage of multiple myeloma. Treatment isn't based on stage alone. Symptoms depend on which parts of the body are affected. Treatment decisions also consider chromosome changes, how well your kidneys work and your overall health. Treatment also depends on whether a stem cell transplant is an option.
Learn about multiple myeloma symptoms and treatment.
Aug. 22, 2026