Why does glandular fever cause fatigue?

Glandular fever is usually caused by a virus that triggers a strong immune response. Chemicals released during that response can leave you drained and unable to manage your usual activity. Sore throat, swollen glands, fever and disturbed sleep may make the fatigue feel heavier. Fatigue is a very common presentation of Glandular Fever, yet fatigue alone can arise from many physical and emotional causes.

Recovery is often uneven. You may feel more capable on one day and need extra rest after ordinary tasks on another.

Give yourself permission to rest, drink enough fluid and eat regular nourishing meals when you can. Break necessary tasks into smaller parts and increase activity gradually according to how you feel. Avoid alcohol while unwell, especially if a clinician has mentioned liver irritation. Contact your clinician before returning to contact sports or heavy lifting, as glandular fever can enlarge the spleen.

Keep a simple note of sleep, activity and symptoms; it can make it easier to explain your recovery at a follow-up appointment.

Seek urgent care for trouble breathing or swallowing, severe pain in the upper left side of the abdomen, collapse, confusion, or yellow skin or eyes. Arrange prompt medical advice if you are becoming more unwell, cannot drink enough, have persistent high fever, or fatigue is stopping you from managing basic daily needs.

Ask whether your symptoms and examination support glandular fever, whether any tests are needed, and when it is reasonable to resume work, study, exercise or sport. Ask about symptoms that could signal a spleen or liver problem.