Conditions We Treat

Neutropenia.

A low neutrophil count — often mild and harmless, but sometimes a clue worth investigating.

Overview

What is neutropenia?

Neutropenia means a lower-than-normal number of neutrophils — the white blood cells that are the body’s front line against bacterial infection. It is often found on a routine blood test.

How much it matters depends on how low the count is. Mild neutropenia is common and frequently harmless, whereas a very low count increases the risk of infection and needs closer attention. As with other low counts, neutropenia is a sign rather than a diagnosis, so the aim is to find the cause.

Important: a fever in someone known to have a very low neutrophil count (febrile neutropenia) can be a medical emergency and needs urgent assessment — contact your doctor immediately or attend your nearest emergency department.

Causes

Common causes

Viral infections — a very common and usually temporary cause
Medications — a number of drugs can lower the neutrophil count
Benign ethnic neutropenia — a harmless, lifelong lower baseline count seen in some healthy people
Autoimmune conditions and some chronic illnesses
Vitamin B12 or folate deficiency
Bone marrow causes — less common, such as MDS or leukaemia, particularly if other blood counts are also low

Diagnosis

How it's investigated

A single low result is often repeated first, as counts fluctuate and can dip temporarily after a viral illness. Assessment includes a blood film reviewed by a haematologist, checking whether other blood counts are affected, and targeted tests such as B12 and folate. Persistent or unexplained neutropenia, especially with other low counts, may warrant a bone marrow test.

When to refer

When to see a haematologist

Persistent or unexplained

Neutropenia that doesn’t resolve or has no clear cause.

Severe neutropenia

A very low count, or neutropenia with recurrent or serious infections.

More than one low line

Neutropenia together with low red cells or platelets.

Common questions

Frequently asked

Is neutropenia dangerous?

It depends on how low the count is. Mild neutropenia is often harmless, while a very low count raises the risk of infection. A fever with a known very low count needs urgent care.

What is benign ethnic neutropenia?

It is a naturally lower baseline neutrophil count found in some healthy people, particularly those of African, Middle Eastern or some other backgrounds. It is not a disease and does not increase infection risk.

Do I need a referral?

Yes — a referral from your GP or specialist is needed for Medicare rebates. Your GP can repeat the test and refer you if it persists.

Found to have a low white cell count?

Ask your GP for a referral, or contact our rooms to arrange assessment 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.