Differential diagnosis of osteomyelitis

Osteomyelitis may develop after an operation, an open injury, spread from nearby tissue, or through the bloodstream. Similar symptoms can occur with a fracture, bone tumour, inflammatory arthritis, gout, a pressure injury, or a joint infection. A clinician considers how symptoms began, whether there is a wound or drainage, recent procedures, implanted material, and conditions that affect circulation or immunity.

Blood tests may show inflammation but cannot identify the cause by themselves. X-rays, magnetic resonance imaging, or other scans can show bone or soft-tissue changes. If safe and appropriate, a sample from bone or a deep collection may be tested to identify an organism and guide treatment.

Arrange a medical assessment for persistent, worsening, or deep bone pain, especially when it occurs with warmth, swelling, a wound, drainage, or fever. Bring a list of medicines, recent procedures, injuries, and previous infections. Do not squeeze a wound or start leftover antibiotics; these actions can obscure examination findings and may not treat the responsible organism.

Treatment depends on the confirmed cause. Infection may need targeted antimicrobial treatment and drainage or removal of unhealthy tissue. A complex defect after infection or injury may require specialist reconstruction, sometimes including [Bone Grafting](/treatments/trauma-and-fracture-care/bone-grafting/).

Seek urgent care for rapidly increasing swelling or pain, spreading redness, pus, a high temperature with shaking chills, confusion, faintness, or a limb that becomes cold, pale, numb, or difficult to move. These features can signal a serious infection, circulation problem, or another emergency and should not wait for a routine appointment.

Ask which alternative diagnoses are being considered, whether imaging is needed, whether a culture or tissue sample would change treatment, and what warning signs should prompt immediate review. Ask how to protect movement and the affected area while the diagnosis is being clarified.