Bordetella pertussis diagnosis: how it is checked

A clinician asks when the cough began, whether it comes in bursts, causes vomiting, or follows contact with someone who has pertussis. They check breathing, hydration, temperature, and the chest. The absence of a whoop does not rule out infection, and symptoms can look different in adults and babies.

A nasal or throat sample may be collected for laboratory testing. The usefulness of a test depends on the stage of illness and the sample method, so a clinician may begin management based on the overall picture rather than wait for a result.

Call ahead before visiting a clinic if you have a forceful or persistent [Cough](/symptoms/cough/), so staff can reduce exposure to others. Note the start of symptoms, coughing triggers, medicines, vaccination history, and recent close contacts. Avoid sharing cups and keep distance from babies until advised.

Follow the plan for testing, treatment, and contact precautions. Read more about [Whooping Cough](/conditions/whooping-cough/) and [Antibiotic Treatment](/treatments/medical-management/antibiotic-treatment/).

Seek urgent care for breathing difficulty, breathing pauses, blue or grey lips, severe weakness, confusion, dehydration, or a baby who cannot feed normally. Do not wait for a test result when breathing is becoming harder.

Ask which test is being used, when results are expected, whether treatment should start before the result, and how to protect household contacts while the diagnosis is being clarified.