Phlebitis: Symptoms, causes and when to worry

Phlebitis is the medical term for inflammation in a vein, most commonly in the legs. It typically affects superficial veins near the surface of the skin and is often linked to underlying vein issues such as varicose veins. Although it’s usually not dangerous, phlebitis can be painful and uncomfortable—and in some cases, a warning sign of a more serious problem like deep vein thrombosis (DVT).

What is phlebitis? (Phlebitis meaning)

The word "phlebitis" literally means “vein inflammation.” When it occurs in a superficial vein, it’s also referred to as superficial thrombophlebitis. It often presents as a painful, hardened cord under the skin with redness and swelling. In most cases, it’s a temporary condition, but recurrent episodes should never be ignored.

5 signs and symptoms of phlebitis

The most common phlebitis symptoms include:

• A red, warm area along the vein
• A painful, rope-like vein under the skin
• Local swelling or tenderness
• Pain when standing or walking
• A visible or raised line following the course of the vein

To see how this can look in real cases, you can compare these phlebitis pictures from the leg to your symptoms.

What causes phlebitis in the leg?

The most common causes include:

• Varicose veins or poor venous circulation
• Prolonged inactivity (e.g. long-haul flights or post-surgery)
• Irritation from IV cannulas or injections
• Hormonal factors (e.g. pregnancy or birth control)
• Genetic clotting tendencies

If you want to better understand these underlying triggers, we recommend visiting this page about causes of varicose veins.

Types and stages of phlebitis

What are the 3 types of phlebitis?

1. Superficial phlebitis – inflammation in a vein near the surface of the skin
2. Deep vein thrombophlebitis (DVT) – inflammation in a deep vein, usually involving a blood clot
3. Septic phlebitis – a rare, infected form that requires antibiotics or urgent care

Superficial phlebitis stages generally follow this pattern:

• Stage 1: Redness and discomfort
• Stage 2: Hardened vein with swelling
• Stage 3: Pain reduces, but the vein remains fibrous for weeks
• Stage 4: Underlying cause (e.g. varicose veins) remains untreated

Phlebitis vs cellulitis

Phlebitis is often confused with cellulitis, a skin infection that can appear similar. However, the two conditions differ in origin and treatment. If the redness spreads quickly or you have a fever, cellulitis is more likely. We break down these differences further in our article on thrombophlebitis, where infection-related symptoms are also discussed.

Phlebitis treatment and self-care

Most cases of phlebitis can be treated at home. Common treatments include:

• Wearing compression stockings
• Applying cool compresses
• Taking anti-inflammatory medications (e.g. ibuprofen)
• Elevating the leg
• Gentle walking to stimulate circulation

If symptoms persist or there’s concern about a clot, a medical scan (usually an ultrasound) is essential. If you're unsure when to take it seriously, this page explains when to worry about varicose veins, including phlebitis-related concerns.

When phlebitis may be a warning sign

If you experience phlebitis more than once, or if the symptoms arise spontaneously (without trauma or IV use), it may point to a more serious circulatory issue like chronic venous insufficiency. This is a condition where blood struggles to return to the heart and pools in the legs.

We explore that connection further in our guide to venous insufficiency.

Phlebitis and varicose veins

There is a well-documented connection between phlebitis and varicose veins. Enlarged, twisted veins cause sluggish blood flow, making inflammation more likely. In fact, many patients discover they have varicose veins because they experienced a phlebitis episode.

Learn more about vein deterioration and how it can trigger inflammation in this article about varicose vein facts.

Recognising phlebitis vs DVT: A comparison table

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Summary: Don’t ignore vein inflammation

While phlebitis is often harmless, it’s never wise to dismiss leg symptoms. Whether it's redness, pain, or a hardened vein, these signs can be your body’s early warning system. Timely treatment and understanding the root cause—such as varicose veins—can prevent future complications. At UK Vein Care, we specialise in assessing and treating the full spectrum of vein-related conditions.