Dear doctor, why are people generally more tired when they have a chronic immun disease(virus)?

Viruses: With a viral infection the virus invades the cells as opposed to bacterial infections which are outside the cells. Bacterial infections often make you acutely sicker but respond to antibiotics. Viral infections are often less dramatic but smolder and are not affected by antibiotics, may last longer and may take longer to regain your energy and rebuild the damage done. It may take weeks to feel ok.