Most people with MGUS (approximately 4 out of 5) remain well and never develop any symptoms related to it.
Sometimes, MGUS can be associated with non-cancerous conditions such as inflammation, arthritis or infection.
There is a risk that a small number of people with MGUS might go on to develop cancers affecting the blood after a few years. These include myeloma, lymphoma, Waldenström's macroglobulinaemia, and amyloidosis.
Possible symptoms of these cancers might be: feeling very tired; repeated coughs; colds and other infections; unexplained bruising or bleeding; swollen lymph glands; pain; night sweats; and weight loss.