@kkieft Welcome to Mayo Clinic Connect! My condolences on losing your sister, and kudos to you for going forward with being tested.

As you read the posts here, you will find that many people are handed a diagnosis of MGUS and continue to live on without any progression to smoldering multiple myeloma. And your story is yet another one!

When a blood test is taken, a patient's gender and age are also factored in to the results. That may show up different for everyone. Just a hint! Have you thought about the low back pain being associated with seasonal reduced activity, likewise the fatigue? We often "slow down" in the winter months.
Ginger