A red, hot, swollen and extremely painful joint can be gout. It can also be septic arthritis, an infection inside the joint. The two can look similar, and missing an infection can have serious consequences. See how gout is diagnosed for the role of joint-fluid testing, and gout flare relief only after infection and other urgent causes have been considered when appropriate.
Symptoms that overlap
Both gout and septic arthritis can cause sudden severe pain, warmth, swelling, redness and difficulty moving the joint. Fever may occur with infection, but its absence does not rule infection out.
When to seek prompt medical assessment
Seek urgent care when a painful swollen joint is a first episode, the diagnosis is uncertain, you feel systemically unwell, you have fever, there is a recent wound or procedure, or the symptoms are unusually severe or different from your typical gout.
How clinicians tell them apart
Blood tests can support the assessment, but joint aspiration is often the key test when infection is a serious possibility. The fluid can be examined for crystals and tested for bacteria.
Can gout and infection occur together?
Yes. Finding urate crystals does not make infection impossible. Clinical judgment and microbiology testing matter when the risk is significant.
Why this page is deliberately cautious
Online symptom checklists cannot safely rule out a joint infection. NICE specifically advises immediate referral according to the local pathway when septic arthritis is suspected.
This article is educational and is not a substitute for urgent medical assessment when infection is possible.
Sources
Related guide: Gout or Something Else? Conditions That Can Look Like Gout compares joint infection, CPPD, injuries and other common gout look-alikes.
Evidence checked September 2026.