Deep vein thrombosis (DVT) occurs when a blood clot forms in the deep veins of your body. While DVT is most common in the legs, it can happen anywhere in the body, including your arm, torso or around your brain.

A blood clot typically forms in one of 3 ways:

• When the flow of blood in your vein slows 
• When damage occurs to your veins
• If your blood becomes more likely to clot

When blood clots form to repair damage to a blood vessel and stop bleeding, they can be lifesaving. However, blood clots can also form inside a vein inappropriately, which disrupts blood flow. This can happen when your muscles aren’t moving in a way that promotes healthy blood flow or when a disease causes blood to clot abnormally.

Deep vein thrombosis symptoms include:

• A blue, purple or red tint to skin, which may feel warm to the touch
• Pain, tenderness or cramping in your leg, often near the calf muscle
• Swelling in 1 or both legs

Deep vein thrombosis often occurs with no noticeable symptoms. However, if you notice any symptoms of DVT, contact your doctor immediately. DVT can develop into a condition called pulmonary embolism (PE), which is a blood clot in the lungs. 

Symptoms of pulmonary embolism include:

• Chest pain or discomfort that worsens when you cough or breathe deeply
• Coughing up blood
• Fainting
• Feeling dizzy or lightheaded
• Rapid heart rate
• Sudden shortness of breath
• Unexplained cough

Swift diagnosis and treatment can prevent PE — and that could save your life.

There are certain behaviors, genetics and risk factors that can increase your chances of developing blood clots, which can lead to DVT. These include:

• Increased estrogen levels: Being on estrogen or progestin hormone therapy, being pregnant or taking hormonal birth control can raise your DVT risk.
• Physical inactivity: Having a sedentary lifestyle is a major risk factor for DVT. 
• Age: The risk of developing deep vein thrombosis and blood clots increases after 60.
• Other risk factors: A personal or family history of blood clots, obesity and varicose veins are also risk factors for DVT.

While you can’t change some risk factors for DVT, like age and family history, you can take steps to lower your risk:

• Stay active. Regular movement helps keep blood flowing properly. If you sit for long periods — at a desk or on a long flight — take breaks to walk or stretch.
• Maintain a healthy weight. Obesity is a risk factor for DVT, and even modest weight loss reduces your risk.
• Know your medications. Hormonal birth control and hormone therapy can raise your DVT risk. Talk to your doctor about whether your medications affect your risk and what you can do about it.
• Talk to your doctor before and after surgery. Periods of immobility during recovery can increase DVT risk. Your doctor may recommend blood thinners to help.
• Know your family history. If a close relative has had DVT or a blood clot, let your doctor know — it could affect your care plan.

 Tests to diagnose deep vein thrombosis include:

• Blood tests: Bloodwork may be taken to check for elevated blood levels of a substance called D dimer, which may indicate DVT.
• Computed tomography (CT) scan: CT scans let your doctor see where there are blood clots in your veins.
• Doppler ultrasound (duplex): This painless and noninvasive test uses soundwaves to generate pictures of your blood vessels and allows your doctor to check for blood clots and monitor the flow of your blood.

Treatment depends on how severe your condition is. Blood thinners are the most common treatment. If medication doesn't work, your doctor may prescribe thrombolytics (clot busters) to actively break up the clot. And if you can’t take blood thinners, an IVC filter can be inserted into a large vein in your abdomen to trap clots before they reach your lungs.