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Phlebitis is not a bacterial infection and you do not need antibiotics.

Phlebitis is an inflammation of a vein. The vein is hot, red and lumpy. The lump is tubular in shape and it is tender to touch, it may throb and walking may be painful. The cause of phlebitis in the leg is most often a clot in the vein just under the skin. It can disperse and the phlebitis then gets better, but sometimes phlebitis is serious and the condition may become dangerous.

What is Phlebitis?

The vein becomes inflamed either due to a blood clot (thrombus) or because the vein walls are damaged. For this reason, the terms phlebitis and thrombophlebitis are used almost interchangeably. There are two types of phlebitis – superficial phlebitis affects the veins close to the surface of the skin and it is not usually too serious; deep vein thrombophlebitis is much more serious and it affects the larger, deeper veins, frequently in the legs. Deep vein thrombophlebitis (DVT with inflammation)  can be very serious if a blood clot breaks away and travels to the lungs, which would result in a pulmonary embolism (PE).


How do I know if I have phlebitis?

As you can see in this photograph of phlebitis, the skin over the vein is often discoloured but sometimes there may be nothing to see, particularly if the vein is a little deeper. This patient had quite  a lot of tenderness.  An ultrasound scan confirmed that there was clot in the vein and blood-thinning medication was prescribed (anticoagulants).

So what is the best treatment for phlebitis?

Self-help measures you can take for yourself include:

  • Keeping the leg raised
  • Wearing compression stockings
  • Use anti-inflammatory medication 
  • Use a cold flannel to ease pain
  • Keep moving to help the flow of blood

Your GP or a hospital specialist might also prescribe anticoagulants (blood-thinners) to stop additional blood clots forming and clot-dissolving medication for cases of deep vein thrombophlebitis.

Phlebitis versus Cellulitis versus Varicose Eczema of the Leg

These three conditions may be difficult to distinguish just by looking at the leg. In phlebitis, the problem is a clot in the vein, in the case of cellulitis the problem is a bacterial infection. For phlebitis, blood thinning medication may be necessary and antibiotics are not needed. In cases of cellulitis, antibiotics are required. Both phlebitis and cellulitis are urgent and potentially very serious. Both phlebitis and cellulitis can be fatal if not treated properly. 

Varicose eczema is a reaction of the skin to the damage caused by faulty leg veins. Varicose eczema can lead to a leg ulcer but it is not urgent and the ulcer (if it does occur) develops slowly. Neither antibiotics nor blood-thinning medication is required for people with varicose eczema.

The only way to accurately diagnose these three conditions is by a duplex ultrasound scan.


Phlebitis is commonly misdiagnosed as an infection and treated with antibiotics.

Essential facts about phlebitis:

  1. Phlebitis is not caused by an infection and antibiotics are not necessary. Recent reviews in the medical literature suggest that antibiotics are frequently prescribed for phlebitis. Not only is this ineffective, but it costs our healthcare system and it may contribute to antibiotic resistance.
  2. Phlebitis most commonly affects the leg veins and it causes swelling, tenderness and redness along the vein. Less common sites include the arm and the chest.
  3. The diagnosis requires a duplex ultrasound scan. Conditions such as cellulitis can mimic phlebitis and therefore confirmation of the correct diagnosis with a duplex ultrasound scan is essential and it ensures that you get the right treatment.
  4. The fundamental problem causing the inflammation in the vein is clot formation which can spread to the deep veins causing a deep vein thrombosis (DVT) and pulmonary embolism (PE). Many experts suggest that the term phlebitis should be replaced by the term superficial venous thrombosis. This term more accurately describes the potential for DVT.
  5. The duplex ultrasound scan should not only check the area that is painful, but both legs should be examined for a possible deep vein thrombosis. When someone has phlebitis, they can be in a so-called hypercoagulable state in which the blood is sticky. That means that clots can develop elsewhere in the body, including in the deep veins of the other leg.
  6. Phlebitis in varicose veins often recurs and people with varicose veins and phlebitis should have treatment to deal with their varicose veins.
  7. Phlebitis in the absence of any varicose veins is a particularly serious condition. Some people with this condition have an unsuspected malignancy and so careful screening is needed to ensure they have cancer treatment as soon as possible. 

Guidelines from both  America and the UK,  indicate that phlebitis in the veins in the legs can give rise to clots that travel to the lungs. These clots are called Pulmonary Emboli (PE’s) and they can be life threatening. The guidelines differ a little but in general, if the phlebitis is longer than 5 cm or within 3-5 cm of a deep vein, anticoagulation is advised.