What Causes Fever? Common & Serious Causes Explained
Fever can be caused by Meningitis, Sepsis, Appendicitis and other conditions. Learn which causes are serious, which are benign, and when to seek urgent medical evaluation.
Updated March 27, 2026
Fever has multiple causes, ranging from benign to serious. The most common include Meningitis, Sepsis, Appendicitis. Meningitis is inflammation of the meninges (membranes surrounding the brain and spinal cord), caused by bacteria, viruses, or fungi. Bacterial meningitis is a medical emergency causing severe headache, neck stiffness, fever, and potentially fatal if untreated.
Clinical Context
The causes of fever range from benign to serious. Identifying the underlying cause requires clinical evaluation. Common causes include Meningitis, Sepsis, Appendicitis, Bacterial Meningitis, and others.
Clinical Pathway
Fever — Symptom HubSymptomMeningitis — Full Condition GuidePrimary CauseMeningitis — Differential DiagnosisDifferentialMeningitis vs. Migraine — Comparisonvs.Sepsis — Full Condition GuideUrgent CauseAppendicitis — Full Condition GuideUrgent CauseBacterial Meningitis — Full Condition GuideUrgent CauseFrequently Asked Questions
Why do I have fever? common & serious causes explained?+
Fever has multiple causes, ranging from benign to serious. The most common include Meningitis, Sepsis, Appendicitis. Meningitis is inflammation of the meninges (membranes surrounding the brain and spinal cord), caused by bacteria, viruses, or fungi. Bacterial meningitis is a medical emergency causing severe headache, neck stiffness, fever, and potentially fatal if untreated.
What is the most common cause of fever?+
Common causes include Meningitis, Sepsis, Appendicitis. The most likely cause depends on age, associated symptoms, and medical history.
When is fever dangerous?+
Seek medical attention if fever is persistent, worsening, sudden in onset, or accompanied by other concerning symptoms.
Can fever be caused by stress or anxiety?+
Yes — psychological stress can contribute to many physical symptoms, but organic causes should be excluded by a healthcare provider.
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