Monoclonal gammopathy is a condition where an abnormal protein, known as monoclonal protein or M protein, is produced by a single clone of plasma cells in the bone marrow. This can lead to an increase in the level of immunoglobulins, which are antibodies that help fight infections. While it can be benign, it may also indicate underlying diseases, such as multiple myeloma or Waldenström macroglobulinemia. Diagnosis typically involves blood tests to measure protein levels and identify the presence of M protein. In many cases, individuals with monoclonal gammopathy do not experience symptoms and may require regular monitoring. Treatment is only necessary if the condition progresses to a more serious illness.