Giardia and fever: what to know

Giardia is a parasite that can irritate the small intestine. Typical illness includes loose or greasy-smelling stools, wind, cramps, nausea, tiredness and reduced appetite. Fever is not a defining feature, so a raised temperature can reflect a separate viral or bacterial illness, another gut infection, or a complication that needs checking. The symptoms and their timing matter: illness after unsafe water, travel, swimming, or contact with someone who has prolonged diarrhoea can support a giardia assessment, but cannot confirm it.

Drink frequent small amounts of fluid and consider an oral rehydration solution if diarrhoea is substantial. Eat simple foods as tolerated, rest, and wash hands carefully after using the toilet. Avoid preparing food for other people while diarrhoea continues. A clinician may request stool testing, especially when symptoms persist, recur, follow travel, or affect a child. Do not start leftover antibiotics or antiparasitic medicine without advice; the right treatment depends on the test result and your health history.

Arrange prompt medical advice for fever with ongoing diarrhoea, worsening abdominal pain, repeated vomiting, marked weakness, or reduced urination. Seek urgent help for confusion, fainting, severe dehydration, blood in the stool, trouble breathing, or a child who is unusually difficult to wake. A fever in an infant, pregnancy, older age, or a person with reduced immunity deserves a lower threshold for assessment.

Ask whether stool testing is appropriate, whether the fever suggests another source, how to replace lost fluid, and how long to avoid cooking for others. Mention recent travel, untreated water, swimming, household illness, medicines, pregnancy, and any long-term condition.