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Post Surgical Fever - Causes, Types, Treatment and Prevention.

Written by
Dr. Archana
and medically reviewed by Dr. Pandian. P

Published on Feb 09, 2023   -  6 min read


Postoperative fever occurs in patients after surgery, and the article below will explain in detail the causes of postoperative fever and its significance.


Surgery is tough on the body. As a result, it is common to experience a fever in the first 48 hours after surgery. Postoperative fever is a rise in temperature in the hours or days following surgery. Therefore, a fever after surgery can be expected and not considered concerning. Postoperative fevers, however, occasionally indicate an underlying issue.

Although 98.6°F is the ideal body temperature, some people have a little higher or lower temperature. Depending on the individual, anything between 97°F and 99°F can be considered normal. A temperature around 103°F typically is not a cause for alarm if they have not recently had surgery. However, it is best to call the doctor if the fever is higher than this, irrespective of whether a person has recently undergone surgery.

What Causes Post-Surgical Fever?

Postoperative fever can have a variety of causes. Some possible reasons include the following-

  • Infection - This is the most common cause of postoperative fever. Infections can occur at the surgical site or elsewhere in the body.

  • Inflammation - Inflammation can occur in response to surgery or due to other underlying conditions.

  • Blood Clots - Blood clots can form after surgery and cause fever if infected.

  • Anesthesia - Some may develop a fever due to anesthesia used during surgery.

  • Medications - Certain medications, such as antibiotics, can cause fever as a side effect.

  • Dehydration - Dehydration can cause a fever because it disrupts the body's ability to regulate its temperature.

  • Urinary Tract Infection - A urinary tract infection (UTI) can cause fever after surgery, especially if the person has a catheter.

  • Pulmonary embolism: A pulmonary embolism is a blood clot in the lungs that can cause fever if it becomes infected.

  • Heat Stroke - If a person is exposed to high temperatures or becomes too active too soon after surgery, they may develop a fever due to heat stroke.

  • Stress - The stress of surgery and the body's natural healing process can sometimes cause a fever.

  • Sepsis - Sepsis is a severe infection that can cause fever and be life-threatening if not treated promptly.

  • Reactions to Suture Materials - Some people may develop a fever due to the materials used to close the surgical incision, such as sutures or staples.

  • Tissue Damage - If the surgical site becomes damaged, it can cause inflammation and fever.

  • Acute Respiratory Distress Syndrome (ARDS) - ARDS is a condition that causes fluid buildup in the lungs and can cause a fever.

  • Endocarditis - Endocarditis is an infection of the heart's inner lining that can cause a fever.

What Are the Different Grades of Fever?

Several conditions can result in a fever after surgery, and fever are graded into categories as follow:

  1. Low-grade fever.

  2. Moderately high fever.

  3. High-level fever.

1. Low-Grade Fever - A temperature is considered a low-grade fever if the temperature is just one or two degrees above the average value (98.6 degrees). It is wise to inform the surgeon. A fever of 99 degrees Fahrenheit is considered normal in the first week when the incision heals. Inform the surgeon immediately if a person has a fever and the incision is not healing correctly. A patient may require medical care. A low-grade fever should also be reported to the surgeon if it persists for more than a few days.

2. Moderately High Fever- A temperature of 100.6 and 102 F is considered mild. Fever in this range should be taken to the surgeon. These signs may indicate the beginning of a problem. It is essential to get medical attention. If a person also has a fever along with any of these signs:

  • Nausea.

  • Vomiting.

  • Increased pain at the surgical site without any apparent reason.

  • Confusion or disorientation.

  • Drainage or pus from the incision or suture site.

  • A rash near the incision.

  • Breathing difficulty.

  • If the temperature does not subside after an hour of taking fever medication (antipyretic medicine), then patients should also consult a doctor.

3. High Fever Patients- Fevers over 102 degrees Fahrenheit should seek emergency medical assistance. This high fever may indicate a dangerous infection. It may also mean an issue with the surgery site or a drug reaction.

How to Treat Postoperative Fever?

Patients can treat a fever with over-the-counter drugs if they have had surgery within the past two days and it is one or two degrees higher than usual. If a person gets a fever five days after surgery or longer (but less than 30 days), it is more likely to occur due to an infection. Ibuprofen and acetaminophen can help lower high fever and ease discomfort. It is advisable to call the doctor immediately if the body temperature is two degrees or higher than usual. A person may require additional care, such as:

  • Anticoagulants to treat VTE.

  • Chest physiotherapy, such as postural drainage, for atelectasis.

  • Antibiotics treat an infection close to the surgery site or in other body parts.

When Does Postoperative Fever Become a Significant Issue?

A fever sometimes represents the body's reaction to surgery but can also indicate an underlying issue. If a person recently underwent surgery and has a fever higher than 101°F, they should contact their doctor immediately. Additionally, if the person develops a fever several days following the treatment, they should contact their doctor. During the healing phase, the patient should be observant of any indications of a surgical site infection or in any regions of intravenous treatment. The signs of illness are as follows:

  • Swelling and redness are typical indicators of disease.

  • Increased discomfort or sensitivity.

  • Draining a murky liquid.

  • Heated pus.

  • Unpleasant odor.

  • Bleeding.

Other indications that the severity of a postoperative fever may be higher include the following:

  • Pain in the legs.

  • Severe headache.

  • Difficulty in breathing.

  • Irritation during urination.

  • Excessive urination.

  • Vomiting and nausea.

  • Severe diarrhea or constipation.

After surgery, it's critical to seek medical attention immediately to prevent any long-term problems for any signs of infection or other issues. Ask to speak to a nurse or go to an urgent care clinic if you cannot reach your doctor.

What Is the Prevention for Postoperative fever?

There is no definitive strategy to prevent postoperative fevers. However, healthcare professionals keep hospitals and operating rooms free of bacteria, viruses, and fungi. Therefore, patients need to consult doctors or other hospital staff about their sanitation practices and policies if they are worried about acquiring an infection while receiving care there.

A patient can do a few things to lower the likelihood of complications following surgery.

Quit Smoking - Before surgery, give up smoking. Smoking raises the chances of blood clots and infection.

Avoid Shaving - Shaving anywhere close to the site of the procedure can contaminate the skin. Speak with the surgeon first to determine whether shaving is required if there is a lot of hair around the surgical site.

Cleaning of the Body - A person should use surgical soap to wash her hands the night before and the morning of the procedure.

Inquire About Antibiotics - People should ask doctors if they intend to give antibiotics as prophylaxis.

Observe Directions - The doctor should provide all the details a person requires regarding treatment, wound care, including drugs, and frequency of bandage changes. A person should follow all instructions carefully.

Sanitize Hands - Before touching the incision for any reason, including scratching an itch, a person should wash hands with soap and warm water.

Self Care – Instruct visitors to wash hands before entering the hospital after surgery. Procure appropriate assistance. Before getting help with catheters or wound care, ensure caregivers have sanitized their hands.

Invoke Assistance - A person should call the doctor immediately if they develop a high fever or other strange symptoms.


A mild temperature following surgery is average. Temperature between 99 and 101 degrees Fahrenheit may subside naturally or with over-the-counter treatment. Nevertheless, it may be wise to discuss it with the surgeon. A fever may indicate that an illness is spreading throughout the body. To pinpoint the particular problem, the medical staff can perform testing. Antibiotics or another type of treatment may be required.

Additionally, it is crucial to get medical attention immediately if a person has nausea, vomiting, shortness of breath, confusion, or signs of wound infection. Finally, remember that a low-grade fever is extremely typical—indeed, practically expected—in the days following surgery. Although a slight fever is not life-threatening, a person should be alert and inform their healthcare professional if it worsens.

Article Resources

Last reviewed at:
09 Feb 2023  -  6 min read




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