What should you know about dengue fever onset?

Symptoms do not always start immediately after a bite. A person may first notice a general unwell feeling, then fever with headache or body aches. Nausea, reduced appetite, or a rash can also occur. These symptoms overlap with other infections, so onset alone cannot confirm dengue. Tell a clinician about recent travel, mosquito exposure, and the date symptoms started. The [Dengue Fever](/conditions/dengue-fever/) page explains the wider illness.

The pattern can change as the fever settles. That is why monitoring matters even when one symptom seems to improve.

Rest, drink suitable fluids if you can, and record fever, vomiting, urine output, rash, pain, and any bleeding. Arrange a [GP Consultation](/treatments/consultations-and-assessment/gp-consultation/) to discuss examination and testing. Ask before taking medicines for pain or fever; aspirin and some anti-inflammatory medicines may be unsuitable when dengue is possible. Avoid mosquito bites while unwell.

Seek urgent medical attention for severe abdominal pain, repeated vomiting, bleeding, black stools, fainting, confusion, breathing difficulty, or inability to drink. Easy bruising should be reported promptly, particularly if it is new or accompanied by bleeding; see [Easy Bruising](/symptoms/easy-bruising/).

Ask whether the onset pattern fits dengue or another illness, which test is useful now, how to manage fluids, which medicines are safe for you, and which changes should prompt emergency care. Mention pregnancy, childhood age, older age, or long-term conditions because these can affect advice.