Fever After Surgery

When a Fever After Surgery Is Serious and Needs Medical Attention

adult man taking his temperature
Checking For a Temperature After Surgery. Medioimages/Photodisc/Getty Images

Patients are frequently alarmed when their temperature is elevated in the hours and days following surgery.  Throughout our lifetime, we are taught that having a fever is a bad thing, and after having surgery people are often very alarmed by the idea of having a temperature.  The presence of an elevation in body temperature is not necessarily cause for alarm, and when mild, is a normal part of the recovery process.

Temperature After Surgery

The reality is that a slight elevation in temperature after surgery is expected, and how a fever is treated, and how worrisome that fever is, depends on multiple factors.  A temperature of 99 is very common after surgery, especially the first week after a surgery with a healing incision and is not considered a "fever". If you are concerned about having a fever it is important to take your temperature daily in the week following surgery, or if you feel chilled or feverish.

A fever, or a temperature above 101.5,  along with an incision that does not appear to be healing well is absolutely cause to update your surgeon and to possibly seek medical attention. Keep in mind that a fever after surgery is the most common complication that patients face, when you include low grade temperature increases that are below 101. For most patients, a fever isn't reason for alarm, but it should never be ignored.

A serious fever -- 102 degrees F or higher -- indicates the need for medical attention, but all fevers over 100 F should be reported to your surgeon.

The more time that passes between the day of your surgery and the day of your fever, the less likely the fever is to be related to your surgery, especially if weeks have passed with no issues.

Treatment of Fever After Surgery

The cause of a fever may not be obvious, and a low-grade fever may not even warrant treatment beyond over the counter medications such as Tylenol or Ibuprofen.  These medications are used to decrease body temperature.   Often, a fever between 99 and 101 is allowed to run its own course without medication. Higher temperatures typically require greater attention and may require testing to identify the cause.

If you are taking pain medication that contains Tylenol or Ibuprofen routinely to manage your pain after surgery, you could potentially have a fever and not realize it as these medications work to reduce fever as well as pain. 

Bringing down a fever with medication may not be good enough.  You may have an infection that requires prescription antibiotics to treat, specialized wound care, or both.  With higher fevers, blood, urine and wound cultures are often done to make sure the blood, urinary tract and surgical wound are not growing a bacterial infection.  

Many surgeons will err on the side of caution and begin antibiotics before the culture results are available in order to prevent an infection that may be present from worsening. 

Causes of Fever After Surgery:

  • Infection is a common cause including pneumonia, urinary tract infection, infected incision and abscess. Infection is a serious potential complication in the days and weeks after surgery and should not be ignored.
  • Sepsis, an infection that reaches the bloodstream, can potentially be extremely serious and it treated with antibiotics and may result in a return to the hospital for treatment.  Severe cases will require IV antibiotics and can lead to hospitalization.
  • Blood Transfusion: Many patients experience a low grade temperature elevation after receiving donated blood.
  • Deep Vein Thrombosis: This is a blood clot that forms in the extremities, typically the legs, and leads to pain and swelling at the site.
  • Peritonitis, an infection in the abdomen often caused by a leak at the surgical site, is a serious complication of abdominal surgery and can be caused by an accidental wound being made in the abdomen. 
  • Urinary Tract Infection: during longer surgeries a foley catheter is often placed to drain urine from the bladder during the procedure.  The insertion of a foley catheter increases the risk of having a urinary tract infection in the days that follow.

Non-Surgical Reasons For Fever:

  • Virus, such as the flu
  • Cold
  • Sore Throat
  • Neurological Fever: This type of fever is caused by a brain injury and will not respond to normal interventions, such as Ibuprofen.
  • Other illnesses unrelated to the procedure.


Evaluating Postoperative Fever: A Focused Approach. Cleveland Clinic Journal of Medicine. April 2011. http://ccjm.org/content/73/Suppl_1/S62.full.pdf

Fever In the Postoperative Patient: A Chilling Problem. The Canadian Journal of CME. Accessed April 2011. http://www.stacommunications.com/journals/cme/2004/May/PDF/093.pdf

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