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is a test that shows blood flow through a vein. Contrast liquid is used to help the vein show up in x-rays. Venography can be used to find current blood flow problems or the effects of a past problem. Blood flow may be blocked or slowed from inflammation, a tumor, or a blood clot. Venography may be used if other tests cannot find the cause of your health problem. The results will help your healthcare providers make or change treatment plans.

How to prepare for the test:

  • Your healthcare provider will tell you how to prepare. He or she may tell you not to eat or drink anything for a certain time before the test. Arrange to have someone drive you home after the test.
  • Tell your provider about all the medicines you currently take. He or she will tell you if you need to stop any medicine for the test, and when to stop. He or she will tell you which medicines to take or not take on the day of the test.
  • Tell your provider about all your allergies. It is important to tell him or her if you had an allergic reaction to contrast liquid. Your provider may give you medicine before the test to prevent an allergic reaction. During the test, tell the provider right away if you have symptoms of an allergic reaction. Examples include trouble breathing, feeling lightheaded or dizzy, or a racing heartbeat.
  • Tell your provider if you have a kidney condition. Contrast liquid can damage the kidneys. Tell your provider about all other medical problems or conditions you have.
  • If you are a woman, tell your provider if you know or think you are pregnant.

What will happen during the test:

  • Medicine will be applied to numb the skin over the catheter site. The site is usually a vein in foot or arm. Your provider may need to use more than one vein, but this is not common. Your healthcare provider will insert a catheter into the vein.
  • Contrast liquid will be injected through the catheter. You may notice a warmth or burning feeling as the liquid is injected. This is expected and should pass quickly. Your provider may put a tourniquet on your leg if the test is for DVT. The tourniquet helps contrast liquid move into deeper leg veins. Moving x-ray pictures will be taken of blood flow through the vein being checked.
  • Liquid will be put through the catheter to flush the contrast out of your body. Then the catheter will be removed. The insertion site will be covered with a bandage. Pressure may be applied to help stop any bleeding.

What to expect after the test:

  • You may have some pain or bruising at the catheter site. This is expected and should get better in a day or two.
  • You will need to drink more liquid than usual for a few days. Liquid will help flush the contrast liquid out of your body. Your healthcare provider will tell you how much liquid to drink each day.
  • You may get the test results right away, or you may need to come back in. The result is considered normal if blood flowed freely through the vein. Your healthcare provider will tell you when to come in to get the results.

Risks of venography:

The vein used for the test may be damaged. You may have an allergic reaction to the contrast liquid. Your kidneys may be damaged during the test. You will get radiation from the x-rays. Radiation increases the risk for certain types of cancer. The test may also cause a blood clot to form in your vein. You will need treatment if a clot develops.

Call your local emergency number (911 in the US) if:

  • You have numbness or tingling in an arm or leg.
  • You have any of the following signs of an allergic reaction to the contrast liquid:
    • Chest pain or trouble breathing
    • Dizziness or fainting
    • Swelling of your mouth or face
    • Nausea or vomiting
    • Sudden decrease in urination
    • A rash, itching, or swollen skin

Seek care immediately if:

  • The bruise where the catheter went in suddenly gets bigger.
  • You have pain or bleeding at the catheter site.
  • You have signs of an infection, such as redness and swelling at the catheter site.

Call your doctor if:

  • You have questions or concerns about your condition or care.

Care for the catheter site:

  • Keep the bandage on the catheter site for 1 day. Then you can remove the bandage. If the area starts bleeding, apply firm pressure for 10 minutes. Use gauze or a clean towel to apply pressure.
  • Check the catheter site for signs of infection, such as redness, swelling, or pus.
  • Ask when you can bathe after your procedure. Your healthcare provider may tell you to take a shower instead of a bath if the bandage is still in place. Cover the bandage and keep it dry during the shower. Pat your skin dry. Do not rub over the catheter site to dry your skin.
  • Ice the area to reduce swelling, tenderness, and pain. Use an ice pack, or put crushed ice in a plastic bag. Cover the bag with a towel before you apply it to your skin. Apply it for 20 minutes every hour, or as directed.

Drink liquids as directed:

Liquids will help flush the contrast liquid out of your body. Ask how much liquid to drink after your procedure, and which liquids to drink. Your healthcare provider may tell you to drink extra liquids for 1 or 2 days after your procedure.


For the first 12 hours, go slowly and be careful. Rest as needed. Do not climb stairs, drive, bend, or lift heavy objects. These activities may put too much pressure on the catheter site and increase your risk for bleeding. Ask your healthcare provider when you can return to your normal activities.

Follow up with your doctor as directed:

Write down your questions so you remember to ask them during your visits.

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The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

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