• Inflammatory Response: The body's normal response to surgery involves an inflammatory reaction. Fever can occur due to the release of inflammatory mediators as part of the healing process.
• Infection: Postoperative fever can be a sign of infection, such as surgical site infection (SSI), urinary tract infection (UTI), pneumonia, or systemic infections like bloodstream infections (sepsis).
• Atelectasis: Collapse or incomplete inflation of the lung tissue can occur after surgery, causing fever due to localized inflammation.
• Drug Reactions: Some medications administered during or after surgery can lead to fever as an adverse reaction.
• Deep Vein Thrombosis (DVT) or Pulmonary Embolism (PE): These complications post-surgery can lead to fever, especially if there's an associated infection.
• Tissue trauma: Fever can also occur as a response to tissue damage during surgery.
• Hematoma or Seroma Formation: Accumulation of blood or serous fluid at the surgical site can cause localized inflammation and fever.
• Reaction to Anesthesia: Anesthesia-related factors or reactions can occasionally cause postoperative fever.

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