Encephalitis Symptoms & Diagnosis

Symptoms

The symptoms may range from mild, such as fever and headache, to severe, such as seizures , loss of consciousness, and permanent neurological damage. Death may also result.

Symptoms include:

Fever
Weakness, severe fatigue
Headache
Sensitivity to light
Stiff neck and back
Vomiting
Changes in consciousness
Muscle aches
Rash
Personality changes
Confusion
Irritability
Seizures
Partial or complete paralysis
Progressive drowsiness
Yawning
Trouble walking
Trouble speaking
Trouble swallowing

Diagnosis

The doctor will ask about your symptoms and medical history, and perform a physical exam.

Tests may include:

Blood tests—to look for signs of infection
Spinal tap —to test spinal fluid for signs of infection
CT and/or MRI scans of the head—to look for abnormal areas of enhancement, hemorrhage, or edema in the brain
Electroencephalogram (EEG)— to look for abnormal electrical activity in the brain
Brain biopsy —removal of a small sample of brain tissue to test for signs of infection

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition. Copyright © 2026 EBSCO Publishing All rights reserved.