Thrombophlebitis is caused by a blood clot, typically in the legs, but clots can also appear in the neck and arms.

Thrombophlebitis is inflammation of a vein caused by a blood clot. It typically occurs in the legs. A blood clot is a solid formation of blood cells that clump together. Blood clots can interfere with normal blood flow throughout your body, and are considered dangerous. Thrombophlebitis can occur in veins near the surface of your skin or deeper, down in between your muscle layers.

Read more: How to tell if you have a blood clot »

This condition usually occurs in your legs, but it’s possible to develop thrombophlebitis in other parts of your body. Blood clots can cause swelling in the veins of your neck or arms, but this is rare.

Thrombphlebitis affects superficial veins and is a different condition than a deep vein thrombosis (DVT). Symptoms of thrombophlebitis include swelling, redness, and tenderness over the affected vein.

A blood clot causes thrombophlebitis. Inactivity, such as being bedridden after trauma or surgery, is a major cause of blood clots. You can also develop a blood clot if you sit still for too long, such as during a plane ride or a car ride.

Standing up, stretching, and moving your feet periodically during long flights or car rides can help reduce your risk of blood clots. Movement promotes circulation, which discourages the blood cells from sticking together.

You might also develop blood clots if you have injured your blood vessels. Trauma to the limb in question may cause injury to a vein. You may also sustain injury to a blood vessel from intravenous (IV) needles or catheters during a medical procedure. This type of injury is a less common cause of blood clots.

There are also some things that may cause blood to clot more easily. These include:

  • having a pacemaker
  • having a central venous IV line
  • having cancer
  • having an inherited condition that causes your blood to clot too much
  • being pregnant
  • being obese
  • having varicose veins
  • being on hormone therapy, including some birth control pills
  • smoking
  • having a personal or family history of thrombophlebitis
  • having an h/o stroke
  • being older than 60 years of age

Read more: Where can blood clots form? »

The symptoms of thrombophlebitis depend partly on which kind you have. You can experience the following symptoms near the affected area if you have either kind of thrombophlebitis:

  • pain
  • warmth
  • tenderness
  • swelling
  • redness

Superficial thrombophlebitis sometimes causes the affected vein to become visibly engorged and red.

In some cases, your doctor won’t need to do any major tests to identify the problem. The appearance of the area and your description of your symptoms may be enough to diagnose this condition.

If the appearance and description of the condition doesn’t provide enough information for your doctor to make a diagnosis, they may use an imaging technique to see whether a clot is present. Options include an ultrasound, a CT scan, and an MRI scan.

In other cases, your doctor might choose to perform a venogram. This involves injecting a dye into your vein that shows up on X-rays. Your doctor will then take X-ray images to see whether you have a clot.

Your doctor might recommend that you take care of your condition at home if you have superficial thrombophlebitis. They’ll give you instructions that may include:

  • applying heat
  • wearing support stockings
  • keeping the limb elevated
  • using anti-inflammatory medications, such as ibuprofen (Advil, Motrin)
  • taking antibiotics

Your doctor might need to remove the vein if the one with superficial thrombophlebitis becomes permanently unsightly or painful, or if you have this condition in the same vein more than once. The procedure is known as vein stripping. This type of procedure shouldn’t affect your circulation. Veins deeper in the leg can handle the increased amount of blood flow.

Patients with superficial thrombophlebitis usually do not need blood thinners. However, if the clot is near the junction of one of your deep veins, blood thinners can help reduce the risk of the superficial clot becoming DVT. If DVT isn’t treated, it can lead to a pulmonary embolism (PE), or a blood clot in your lungs. A PE can be life-threatening.

Stretch or walk around regularly if you sit at a desk for long periods or if you’re taking a long trip in a car or airplane. Sitting still for too long can lead to thrombophlebitis.

Your doctor will change your IV lines regularly if you’re in the hospital. They might also give you medications to help prevent thrombophlebitis depending on your condition and other factors.