Deep vein thrombosis (DVT) is a serious condition that happens when a blood clot forms deep inside in a vein, usually in your legs. Popliteal vein thrombosis (PVT) is a type of deep vein thrombosis that affects one of the blood vessels behind your knees. Both DVT and PVT can sometimes be mistaken for a less-dangerous condition called a Baker’s cyst.
What Is DVT?
When you have DVT, you have a blood clot in a vein, a vessel that carries oxygen-low blood toward your heart after delivering the oxygen to your tissues. A clot is a thick clump that can keep blood from getting through smoothly. The medical term for a blood clot is “thrombosis,” and it can be dangerous when it happens in a blood vessel.
DVT is more likely in people over 60, and those with a family history of the condition. You could get one if you had recent surgery or pregnancy if or don’t move for a long time, such as when you’re on bed rest. Black people have the highest rates of DVT, followed by white people, Latinx people, and Asian people. Men are at slightly higher risk than women.
Most often, clots form in the lower part of your body such as your legs or pelvis. But you can also get them in your arms.
DVTs can trigger serious issues or even death if they break free from their original spot and travel through your bloodstream to your lungs. This blockage is called a pulmonary embolism (PE). PE can damage your lungs or even stop blood from getting to them altogether.
What Is Popliteal Vein Thrombosis?
Your popliteal vein is a vessel that carries blood from your legs back to your heart. It runs behind your knee and up the back of your thigh. Doctors call it a “deep vein” because it’s far underneath your skin.
As with DVTs in other places, a blood clot in this vein could result in a pulmonary embolism.
What Is a Baker’s Cyst?
This forms when your body makes too much of the fluid that keeps your knee joint moving smoothly. It can happen if you hurt your knee or have a condition that affects your joints, like arthritis. It’s also called a popliteal cyst because it forms at the back of your knee.
A Baker’s cyst can make your knee feel swollen, stiff, or uncomfortable. In rare cases, it can break open and cause fluid to leak down into your lower leg. That can hurt and lead to more swelling.
You can get a Baker’s cyst at any age, though they are most common in people ages 30-70.
Similar Symptoms of Baker’s Cyst, Popliteal Vein Thrombosis, and DVT
DVT, whether it’s in the popliteal vein or elsewhere in the leg, has some of the same symptoms as a Baker’s cyst. That can make it hard for your doctor to know which one you have, especially if the cyst has broken open.
Signs of both conditions can include:
- Swelling in your leg
- Pain when you stand or walk
- Redness or warmth in the swollen area
- Bruising or discoloration
- Tenderness in the swollen area
DVTs and Baker’s cysts can both show up as swelling without discomfort, making them both sometimes hard to notice. You might find it harder to bend or move your leg with both.
When a Baker’s cyst ruptures, you may feel a sharp pain in your knee, and you’ll see swelling down your calf. Your calf may also look red. These symptoms are similar to DVT in your lower leg.
Which Is Which?
If you have these symptoms, your doctor’s first step will be to look for signs of swelling. They’ll then feel the leg area, including around the back of your knee as you flex it.
They’ll also likely try to gather as much info as possible by asking you questions such as:
- Where is the point of tenderness?
- Is the swelling in one specific spot or widespread?
- Has skin color changed?
- Do you have a fever?
- Was there an injury in this spot recently or in the past?
If that doesn’t give them enough information, they’ll probably recommend an imaging test to get a better picture of what’s going on. These might include:
- Ultrasound, which uses high-frequency sound waves to make a live picture of the inside of your leg on a monitor. The kind of ultrasound used to look for signs of deep vein blood clots is called venous duplex scanning.
- MRI, which uses powerful magnets and radio waves to make a detailed picture of the inside of your legs.
- Venography, which uses a dye to help show problems inside your blood vessels. The dye gives your doctor an idea of how blood is flowing inside your veins.
- A blood test known as the D-dimer test, which measures a protein that’s linked to clotting.
Treatments for DVTs won’t work on Baker’s cysts, and Baker’s cyst treatments won’t help you manage DVTs.
DVT and popliteal vein thrombosis treatments
The treatments for DVT include:
- Medications. Doctors most commonly treat DVT with medications called blood thinners (anticoagulants). Though they don’t get rid of blood clots, they do help keep the clots you have from getting bigger. And they stop new clots from forming.
- Filters. Your doctor can insert a filter into a large vein called the inferior vena cava to help catch and stop any blood clots traveling through your bloodstream before they reach your lungs.
- Thrombectomy. In some cases, your doctor may decide to do a procedure to physically remove a clot using a small flexible tube.
Baker’s cyst treatments
Sometimes, a Baker’s cyst will go away on its own. Mild symptoms can be treated with ice and over-the-counter painkillers. For more serious or long-lasting ones, you might need:
- Medication. To reduce swelling in your knee and help with pain, your doctor may give you a corticosteroid shot.
- Fluid drainage. Your doctor can use ultrasound to help guide a needle into your joint to drain extra fluid.
- Physical therapy. A physical therapist can teach you special exercises to help reduce symptoms and make you stronger and more flexible.
Your doctor may also need to treat any conditions you have that could be causing the cyst.