Blood Clots in a Deep Vein (Deep Vein Thrombosis): What to Know

Deep vein thrombosis (DVT) is when a blood clot forms in a deep vein, such as in the arms, lower legs, thighs, or the area between your hip bones (pelvis).

• Pain.
• Swelling.
• Skin color changes.
• Skin ulcers or sores.

What are the causes?

• A slow down of blood flow.
• Damage to a vein.
• A health or bleeding problem that makes you more likely to get blood clots.

What increases the risk?

• You're older.
• You're overweight.
• You're pregnant or recently had a baby.
• You take certain medicines, such as:
  • Birth control pills.
  • Hormone replacement therapy.
• You smoke or use nicotine or tobacco.
• You have or have had a blood vessel disease or heart failure.
• You have cancer.

• You sit or lie down for long periods of time, other than to sleep at night.
• You're in the hospital or having major surgery.
• You've had a recent bone injury, such as a break.
• You've had recent surgery on your legs.

What are the signs or symptoms?

• An arm or leg turning warm or red.
• Swelling, pain, pressure, or tenderness in an arm or leg.
• Pain in your calf or behind your knee.
• A leg turning very pale or having other color changes.

If the clot is in your leg, your symptoms may get worse when you stand or walk. In some cases, there are no symptoms.

How is this diagnosed?

• Blood tests. These can check how well your blood clots.
• Ultrasound. This uses sound waves to make images.
• CT venogram. Contrast dye is put into a vein, and X-rays are taken to check for clots. This is helpful for veins in your chest or pelvis.

How is this treated?

• The cause of your DVT.
• How big the clot is and where it is.
• If you have more than one DVT.
• Your risk for bleeding or having more clots.
• Other health problems you may have.

• Take a medicine called a blood thinner to stop more clots from forming or current clots from growing.
• Wear compression stockings.
• Have medicines put into your vein to break up the clot.
• Have surgery. You may need this if the DVT is very bad or hard to treat. It may be done to:
  • Remove the clot.
  • Put a filter in a large vein called the inferior vena cava (IVC). This helps keep clots from moving to your upper body.

You may have some treatments for 6 months or longer.

Follow these instructions at home:

If you're taking blood thinners:

• Talk with your health care provider if you have a history of:
  • Internal bleeding.
  • Bleeding ulcers.
  • Strokes.
  • Cerebral aneurysms.
• Take your medicines as told. Take them at the same time each day.
• Talk with your provider before taking any products you can buy at the store.
• Do not do things that could hurt or bruise you. Be careful to avoid falls.
• Wear an alert bracelet or carry a card that says you take blood thinners.
• Be careful when using knives, scissors, or other sharp objects.
• Use an electric razor instead of a blade.

General instructions

• Take your medicines only as told.
• Ask what things are safe for you to do at home. Ask when you can go back to work or school.
• Wear compression stockings to reduce swelling and help prevent blood clots in your legs.
  • Do not let them bunch up when you're wearing them.
  • Avoid wearing other tight clothes around your legs or waist.
  • Do not wear your compression stockings to bed.

Where to find more information

• American Heart Association (AHA) at heart.org. Then:
  1. Click "Search."
  2. Type "venous thromboembolism" in the search field and find the link you need.
• Centers for Disease Control and Prevention (CDC) at cdc.gov. Then:
  1. Click "Search."
  2. Type "venous thromboembolism" in the search field and find the link you need.
• National Heart, Lung, and Blood Institute (NHLBI) at nhlbi.nih.gov/health/venous-thromboembolism.

Contact a health care provider if:

• You miss a dose of your blood thinner.
• You have new bruising.
• You have new or worse pain, swelling, or redness in an arm or leg.
• Your arm or leg is numb or tingling and doesn't get better with treatment.
• Your skin is pale and doesn't get better with treatment.

Get help right away if:

• Your arm or leg starts to turn blue.
• You have a very bad headache or confusion.
• You have signs that a blood clot has moved to the lungs, such as:
  • Feeling short of breath.
  • Pain in your chest, back, or shoulder blade that gets worse.
  • Fast or uneven heartbeats.
  • Feeling light-headed or dizzy.
  • Fainting.
  • Coughing up blood.
• You have signs that your blood is too thin, such as:
  • Blood in your throw-up, poop, or pee.
  • A cut that won't stop bleeding.
  • A menstrual period that's very heavy.

• Do not wait to see if the symptoms will go away.
• Do not drive yourself to the hospital.