Conditions We Treat

MGUS & paraproteins.

A common, usually harmless finding on blood tests — but one worth understanding and monitoring properly.

Overview

What is MGUS?

MGUS stands for monoclonal gammopathy of undetermined significance. It means a small amount of an abnormal protein — called a monoclonal protein or paraprotein — produced by plasma cells has been found in the blood. MGUS itself is not a cancer, causes no symptoms, and usually needs no treatment.

It is common, becoming more frequent with age, and is very often picked up by chance when blood tests are done for another reason. The reason it matters is that a small proportion of people with MGUS — on average about 1% each year — go on to develop a related condition such as myeloma, which is why it is monitored over time.

Assessment

How it's assessed

When a paraprotein is found, the aim is to confirm it is MGUS rather than something that needs treatment, and to estimate your individual risk. This usually involves:

Blood and urine protein tests

Serum protein electrophoresis, immunofixation and serum free light chains measure the type and amount of paraprotein.

Excluding related conditions

Blood counts, calcium and kidney function help exclude features that would point to myeloma or a related disorder.

Risk assessment

The size and type of the paraprotein and the free light chain ratio help estimate risk and set how often you need monitoring. Some people need imaging or a bone marrow test depending on their risk.

Management

What happens next

MGUS is managed by monitoring rather than treatment. This typically means periodic blood tests — more frequent at first, then spaced out if things are stable. The goal is simply to detect any change early, at a point where it can be acted on.

We will let you and your GP know your monitoring schedule and the specific symptoms that should prompt an earlier review, such as new bone pain, unexplained tiredness, or changes in kidney function.

When to refer

When to see a haematologist

A new paraprotein

To confirm the diagnosis is MGUS and not a condition needing treatment.

Risk assessment

To estimate individual risk and set an appropriate monitoring plan.

Changing results

If blood counts, calcium or kidney function change, or new symptoms develop.

GPs are welcome to refer for assessment and a monitoring plan — see information for referrers.

Common questions

Frequently asked

Is MGUS cancer?

No. MGUS is a benign (non-cancerous) condition. It is monitored because it carries a small risk of progressing to a related condition over time, and monitoring allows any change to be caught early.

Do I need treatment?

No — MGUS itself is not treated. The focus is on regular blood tests to keep an eye on it.

Will it turn into myeloma?

Most people with MGUS never develop myeloma. On average the risk is around 1% per year, and regular monitoring is designed to detect any change promptly.

Found to have a paraprotein?

Ask your GP for a referral, or contact our rooms to arrange assessment and a monitoring plan in Footscray.

This page provides general information only and is not a substitute for individual medical advice. It should not be used to diagnose or treat a health problem. Please speak with your GP or haematologist about your own circumstances. Last reviewed August 2026.