Deep vein thrombosis (DVT) is a blood clot that forms in a blood vessel inside your body, far away from your skin, that carries blood toward your heart. This mainly happens in your legs and pelvis. That's called lower extremity DVT. It can also happen in your arms, though not nearly as often. That's upper extremity DVT.
DVT in both the upper and lower body can happen to almost anyone at any age and for many reasons. For example, your vein could have been damaged by an injury or operation. Half of blood clots happen after surgery or being in the hospital.
Blood can pool and is more likely to clot when you have to stay in bed or sit still for a long time, like on a plane or car trip. This mostly causes lower extremity DVT.
Upper extremity DVT can happen in people who have a condition called Paget-Schroetter syndrome (PSS). Typically, young athletes get PSS in the arm they use most for sports like baseball, swimming, or tennis. When you do the same motion over and over, the veins in your neck and shoulder get squeezed. This can trigger a clot.
You're much more likely to get a blood clot in your leg than your arm. Still, upper extremity DVT is happening more often. That may be because more people are getting central lines and pacemakers.
Your chance of getting a clot is higher when you:
They're usually the same, regardless of where DVT is in your body. But symptoms happen only about half the time.
It's important to catch and treat DVT before it causes more problems. The biggest danger is much more likely to happen with lower extremity DVT. The clot could break away from the wall of the vein and travel through your blood to your lungs. Then it's called a pulmonary embolism (PE).
A small clot may damage your lungs. A large clot can be deadly.
You can have PE without any symptoms of DVT. Get medical help right away if:
Other health problems can look a lot like DVT. A torn muscle, a skin infection, or a clot in a vein right under your skin (thrombophlebitis) could cause the same symptoms. Your doctor may do tests to find out what's going on.
Duplex ultrasound is the main way to check for upper and lower extremity DVT. It lets your doctor see inside your body without X-rays. Instead, it uses sound waves to create images. The images can show places where your blood flow slows or stops. Ultrasound gives fast results and doesn't hurt or have side effects.
To get a better view of an upper extremity clot or rule out other problems, your doctor might use CT and MRI imaging tests.
D-dimer is a blood test that looks for a protein left over when your body breaks down clots. A negative test usually means you don't have DVT.
Small clots sometimes dissolve on their own, especially ones below your knee. Big clots that don't move or go away are more serious.
A blood thinner doesn't really thin your blood. But it can keep a clot you have from growing and can stop new clots from forming. You'll probably take it for at least 3 months, though that can vary.
If you have a very large clot that hurts a lot and is causing swelling, your doctor may suggest a medicine to break it up. Clot busters aren't used that often because they can cause more serious side effects than blood thinners.