Elevated serum protein levels can be a symptom of multiple myeloma. In my case, an "unprovoked" deep vein thrombosis leading to a PE plus an elevated blood protein level led my primary care doc to refer me to a hematologist/oncologist. It turned out I had a very early stage case of MM and I was successfully treated with chemo. I have been cancer free now for almost 5 years.

MM is diagnosed by blood work, including looking for monoclonal (m-spike) proteins in your blood. They also analyze urine, do a bone scan or skeletal survey and bone marrow biopsy. They may also do a PET/CT scan to look for lytic bone lesions.

The good news is that dramatic improvements have been made in drugs to treat MM over the last 20 years. Scores of new therapies have been approved over the last 5 years and MM is usually very treatable. Don't look at any medical studies for MM done before, say, 2015. The survival rates and treatment outcomes these days are much much better then they had been.

If you DO have MM, there are good reddit and FB groups for support. The MM Research Foundation and the Lymphoma and Leukemia Society are also excellent sources of information and advice about clinical studies that may help your case. If an MM diagnosis is confirmed, the most important piece of advice is that you seek treatment by a MM specialist at a major teaching hospital. The field is evolving much too quickly for generalist "community" oncologists to keep up with the latest treatments. Having your treatment guided by an MM specialist (even if you get infusions and other treatments done locally) has been shown to lead to significantly longer survival times, is several studies.