Severe headache: what to know

Headache can arise from dehydration, missed meals, poor sleep, stress, heat exposure, viral illness, or a primary headache disorder. Nasal congestion may accompany [Allergic Rhinitis](/conditions/allergic-rhinitis/) or [Chronic Sinusitis](/conditions/chronic-sinusitis/). Fever and body aches can occur with [Common Cold](/conditions/common-cold/) or [COVID-19](/conditions/covid-19/), while travel, fever, or intense heat may point toward [Dengue Fever](/conditions/dengue-fever/) or [Heat Exhaustion](/conditions/heat-exhaustion/) in the right setting. The pain pattern matters more than severity alone.

Rest somewhere cool and quiet, drink fluids gradually, and eat if you have missed a meal. Reduce bright light and screen use while the pain settles. Follow the label for any usual pain medicine and check with a pharmacist if you take other medicines, have a long-term condition, or need frequent doses. Record when the headache began, where it hurts, associated symptoms, and possible triggers.

Seek emergency help for a sudden explosive headache, new weakness or numbness, confusion, fainting, seizure, difficulty speaking, vision loss, a stiff neck with fever, or repeated vomiting. Get prompt medical advice for a new severe headache after a head injury, during pregnancy, with very high blood pressure, or when headaches are becoming more frequent or changing pattern.

Ask what examination or testing is appropriate, whether your symptoms fit migraine or another headache disorder, and how to use pain relief safely. Mention recent illness, heat exposure, fluid intake, sleep, stress, medicines, pregnancy, and any link with anxiety such as [Generalised Anxiety Disorder](/conditions/generalised-anxiety-disorder/).