Difference Between Phlebitis and Infiltration (with Table)

Phlebitis can have other causal factors like bacterial infections and chemical reactions that cause the inflammation of veins. Moreover, in phlebitis, the vein is simply inflamed, while when a patient experiences infiltration the IV fluid percolates into the surrounding tissues.

This is a direct consequence of the catheter backing up from the insertion site and perforating the vein. Unlike infiltration, phlebitis does not cause fluid leakage from the insertion site into the neighboring tissues.

Phlebitis vs Infiltration

The difference between phlebitis and infiltration can be noted in terms of the causes of each medical condition. While phlebitis may be caused by multiple factors including IV catheters, infiltration is caused solely by the perforation of a vein by the IV catheter.

Comparison Table Between Phlebitis and Infiltration

Parameters of ComparisonPhlebitisInfiltration
DefinitionInflammation of a vein that is caused by either IV catheters or bacterial or chemical infections.Vascular trauma that is caused by IV catheters dislodging into the vein or perforating the vein.
Fluid DischargeNo fluid discharge is noted.The fluid is displaced into the surrounding tissue space.
CausesCan be caused by either IV catheters or bacterial or chemical infections.Caused by IV catheters dislodging into the vein.
PerforationThe vein is simply inflamed and not perforated.The vein may be perforated when the catheter backs out from the insertion site.
Distinguished SymptomsPalpable venous cords.Fluid build-up, temperature drop, pale skin, no IV flow.
Blood ClotsThrombosis is common with phlebitis.Blood clots are not common in patients experiencing infiltration.

What is Phlebitis?

The inflammation of the intimal layer of the vein is called Phlebitis. It is commonly experienced as a result of administering intravenous medications in patients.

The word is derived from ‘phleb’ meaning vein and ‘itis’ meaning inflammation in the medication diction. The clotting of blood near the surface of veins cause phlebitis in patients on IV medications. This is known as Thrombophlebitis.

Around 20%-80% of patients on IV medications suffer from phlebitis. The symptoms of phlebitis can range from pain, redness, edema (swelling) and tenderness to the most prominently noted symptom of palpable venous cords.

Although phlebitis can commonly affect patients from the age group of 41-60 years, it can also occur in younger people.

Phlebitis can be divided into 3 categories based on its causal factors. Mechanical phlebitis is the first category that is caused by the insertion of the IV catheter. Bacteria phlebitis is caused by a bacterial infection and finally, chemical phlebitis that may occur as a result of fluids IV catheters or fluids.

It is usually a treatable condition that has to be first ascertained by medical testing. While superficial phlebitis can be treated easily, DVT or Deep Vein Thrombosis needs immediate medical attention.

The condition resolves within a week when treated with proper anti-inflammatory medication. Cold compresses and blood thinners are also used to treat the condition.

What is Infiltration?

Infiltration is another kind of vascular trauma commonly experienced by patients with IV catheters. However, it is different from phlebitis as when patients suffer from infiltration they experience the perforation of the vein and the consequent leakage of IV fluids into the neighboring tissues.

The IV catheter can either puncture the vein by backing out from its site of insertion or puncture the other side of the vein. The most common symptom of infiltration is edema or swelling of the site. Fall in body temperature, pale skin, intense pain, numbness and sensitivity at the site may be classed as distinguishing symptoms of infiltration.

Older patients may be more susceptible to infiltration because of the enhanced fragility of their veins due to old age.

In severe cases, left untreated infiltration can cause long-term tissue damage and necrosis. It can also cause severe nerve compression in the patient. In these cases, the accumulated fluid has to be pumped out immediately to prevent the occurrence of compartment syndrome and lasting damage.

Sometimes it can also result in amputations if treatment is delayed. The treatment for infiltration includes immediate removal of IV catheters, inspecting the inflamed site, elevating the leg or arm, using medications to treat the severe cases of high volume fluid build-up.

Main Differences Between Phlebitis and Infiltration

  1. The main difference between phlebitis and infiltration is the cause of their occurrence. While both can be IV catheter-related complications, phlebitis has a wider range of causal factors that may be responsible for the condition- like chemical and bacterial infections. However, infiltration is solely caused by a dislodged IV catheter.
  2. The second difference between these two medical conditions can be noted in terms of their very definition. Phlebitis is the condition that results in the inflammation of a vein, while infiltration results in the percolation of fluid and its consequent build-up in the neighboring tissue clusters.
  3. Phlebitis can be of 3 varieties: mechanical, chemical and bacterial. This distinction is made on the basis of the causal factors. However, infiltration cannot be divided into categories as it is caused by one overwhelming factor- IV dislodging and vein perforation.
  4. Thrombophlebitis is common in patients who have a history of suffering from phlebitis. This results in the formation of blood clots in the vein. No blood clots are formed when a patient suffers from infiltration.
  5. Although most symptoms may be overlapping for both these medical conditions, there are few that distinguish them. Palpable venous cords is a common symptom exhibited by phlebitis patients. This symptom cannot be seen in patients suffering from infiltration. Fall in body temperature, paleness of skin are some symptoms commonly witnessed in infiltration patients but is not applicable in the case of phlebitis.


Both these medical conditions are commonly associated with IV complications and often they are misidentified as the other. They share several symptoms as well as therapy options. However, the salient differences between the two must be noted so as to prevent misdiagnosis.

Phlebitis may be caused by IV catheters or bacterial and chemical infections. Infiltration is solely caused by IV catheters dislodging fluids into the neighboring tissue area. Infiltration-caused fluid build-up can be very harmful.

Moreover, the vein is simply inflamed under phlebitis while it is perforated when the patient suffers from infiltration. The two conditions also bear subtle differences in terms of symptoms. These differences must be cognized to avoid flawed treatment strategies.


  1. https://journals.sagepub.com/doi/abs/10.1177/108482239400700107
  2. https://journals.lww.com/journalofinfusionnursing/Fulltext/2001/09000/Relationship_Between_Peripheral_Intravenous.8.aspx
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