context: Thrombophlebitis is a problem with your circulation -- how fast blood moves through your veins. It happens when a blood clot slows circulation -- most commonly in your legs, but also in your arms, in some cases. Thrombophlebitis can happen right under the skin or deeper in the leg. " Thrombo" means clot, and "phlebitisâ means inflammation in a vein. That's the swelling and irritation that result after an injury. Most cases of thrombophlebitis that happen in the shallow leg veins begin to go away by themselves in a week or two. But on rare occasions, these blocked veins can lead to infection. They can even lead to tissue damage from the loss of healthy circulation. When the deeper veins in the leg are involved, there are greater risks. A piece of the clot can break off and enter the bloodstream. It can travel far from the site where it formed and cause major problems. If the clot reaches the lungs and blocks circulation there, it can lead to death. To prevent this, your doctor might put you on blood thinners. In more serious cases, your doctor may give you medication to "melt" the clot, cut the swelling, or treat any infection that could develop. First, a blood clot forms. This can be due to several things. Most often, it's caused by blood not moving the way it should through the leg veins. It can happen if you've been on long-term bed rest, such as after a major illness or surgery. Blood clots can also form if you've had to sit for a long time in a place where you couldn't stretch your legs, like on a long flight or drive. Varicose veins can lead to thrombophlebitis, too. They cause your blood vessels to stretch too much. This allows blood to pool in the vessel instead of flowing straight through in one direction. This can lead to blood clots. Anyone who has poor circulation in their legs may be more likely to have this condition. This could include pregnant women, who may develop thrombophlebitis during or after pregnancy. People who've been kept in the hospital on an IV are at risk, too. And while hospital staffers try to lower this risk by changing the spots where IV lines are placed in the body, thrombophlebitis is still possible. Other things that raise your chances of developing this condition include: Having certain cancers Use of the hormone estrogen for birth control or hormone replacement Being over age 60 Obesity Smoking A family history of blood clots Catheters placed in central veins of the arm or leg If the blood flow (circulation) to one of your veins is slowed because of a clot, you might have: Red, swollen, and irritated skin around the affected area Pain or tenderness that gets worse when you put pressure on the affected area A swollen vein that feels like a tough "cord" under your skin Pain when flexing your ankle (keep in mind that thrombophlebitis can happen in other parts of the body, but typically occurs in the legs) Swollen foot or ankle If you have any of these symptoms, see your doctor. They will do a physical exam. They may also do blood and circulation tests, or imaging exams, like a CT scan or MRI. One leg seems warmer than the other or is swollen, red, painful, or irritated The affected limb becomes pale or cold, or you start feeling chills and fever Thrombophlebitis treatment depends on how bad it is. Clots lodged in veins near the surface of the skin often go away on their own in a week or two. But if you do need treatment, your doctor will probably give you something to relieve swelling and pain. He may recommend you elevate your leg or take over-the-counter aspirin or ibuprofen. He might also suggest you apply heat to the affected leg for 15 to 30 minutes two to three times daily. You may need to wear compression stockings. These help improve blood flow to your legs. They also help lessen swelling. If your thrombophlebitis is more severe, your doctor may give you a blood thinner. You can get some of these medications, like heparin, in the hospital through an IV. You can give others, like enoxaparin ( Lovenox), to yourself through shots under your skin at home. They help keep the clot from getting bigger. You may also have to take an oral drug like w arfarin ( Coumadin) for several months or longer to keep clots from coming back. Your doctor will give you regular blood tests to make sure the meds are working. Newer blood thinners, like direct thrombin inhibitors and factor Xa inhibitors, are also available. But doctors don't normally recommend them as the first-line treatment for thrombophlebitis. That's because they cost more and may cause uncontrollable bleeding. They include apixaban ( Eliquis), dabigatran ( Pradaxa), edoxaban ( Savaysa), and rivaroxaban ( Xarelto). Serious cases of thrombophlebitis may need to be treated with antibiotics. These kill infections caused by poor circulation. If there's a high risk of tissue damage, or if your clot comes back, you may need surgery after the inflammation improves. If you have a clot in a deep vein in your leg, your doctor might recommend an inferior vena cava ( IVC) filter. The vena cava is the main vein in your abdomen. The IVC filter prevents clots in your legs from breaking loose and traveling to your lungs. Superficial thrombophlebitis: It's a blood clot in the vein just below surface of your skin. It doesn't usually get to your lungs, but superficial thrombophlebitis can be painful, and you may need treatment. Deep vein thrombosis ( DVT): It's a blood clot in a vein deep in your body. Most happen in your lower leg or thigh, but they may happen in other parts of your body. A clot like this can get loose and travel through your bloodstream. If it gets to an artery in your lungs and blocks blood flow, it's called a pulmonary embolism, which can damage your lungs and other organs and even cause death. Migratory thrombophlebitis: Also called Trousseau syndrome or thrombophlebitis migrans, this clot moves around the body, often from one leg to other. It's often linked to an underlying cancer, especially of the pancreas or lung.