Staging of myeloma

The stage of myeloma shows how quickly or slowly it may develop. It also shows the effects it is having on your body, for example, if your kidneys are affected.

What is staging?

The stage shows how quickly or slowly myeloma may develop using the results of blood tests. It also looks at the effects myeloma is having on your body. Myeloma is staged from stage 1 to 3.

Staging may not affect the treatment you have.

We understand that waiting to know the stage of your myeloma can be a worrying time. We're here if you need someone to talk to. You can:

International Staging System (ISS)

The International Staging System (ISS) for myeloma uses the results of these 2 blood tests to help find out the stage of myeloma:

  • beta-2 microglobulin (B2M)
  • albumin level.

If B2M is raised or if albumin is lower than normal, these can be signs the myeloma is more advanced.

There are 3 stages of myeloma. Stage 1 is the earliest stage and stage 3 is more advanced.

Stage B2M (measured in mg/L)  Albumin (measured in g/dL)  
Stage 1 Normal or near normal (less than 3.5) Normal (3.5 or more)

Stage 2
Normal or near normal (less than 3.5) Low (less than 3.5)
 Raised (3.5 to 5.5) Any level 
 Stage 3  High (5.5 or more)  Any level


Sometimes doctors use an adapted version of the ISS. This is called the Revised International Staging System (R-ISS). This uses:

  • the results of the blood tests from the ISS
  • a blood test called lactate dehydrogenase (LDH)
  • the results of a cytogenetic test (called FISH) on the chromosomes of the myeloma cells.


What is the CRAB Criteria?

Doctors also look at the effect myeloma is having on your body.
They may use the results of tests called the CRAB criteria to assess this:

  • C – Calcium levels are raised.
  • R – Renal (kidney) problems.
  • A – Anaemia (low number of red blood cells).
  • B – Bone damage.

They will ask if you have had repeated infections or symptoms linked to thickening of the blood (hyperviscosity). We have more about symptoms of hyperviscosity in our information about managing symptoms and complications of myeloma.