Leg venography, also called lower extremity venography or phlebography, offers a way for your doctor to visualize the veins in your legs. Veins don’t normally show up on plain X-rays. In a venogram, your doctor injects a special kind of dye into your veins. This dye, called contrast material, is visible on X-rays. It allows your doctor to take images of the veins in your leg.

Your doctor might choose to perform this procedure to find out if there are blood clots in your leg veins or if your veins are damaged or not functioning properly. Your doctor might also order a leg venogram to locate a particular vein or find out why your leg is swollen or painful.

You must tell your doctor about various conditions before you undergo this procedure. It’s especially critical that you tell your doctor if you have allergies to medications, dye, or iodine substances. You should also tell your doctor if:

  • you’re pregnant or breast-feeding
  • you have a history of bleeding problems or kidney problems
  • you have asthma
  • you have diabetes
  • you’re taking metformin (Glucophage)

You should also make sure that your doctor knows about any prescription or over-the-counter medications you’re taking, particularly aspirin or other blood thinners.

During a leg venogram, the following will occur:

  1. You’ll change into a hospital gown and then lie down on an X-ray table.
  2. Your doctor will typically numb an area on your foot.
  3. They’ll then insert a needle connected to an intravenous (IV) line into a vein in your foot.
  4. Dye will flow through this line into your vein. They’ll take X-rays as the dye travels up your leg. Because the dye shows up on X-rays, your doctor will be able to gain a better understanding of what’s happening in your veins.
  5. After your doctor has taken all the needed X-rays, they’ll typically inject saline solution into your IV line. This helps flush out the contrast material.
  6. They’ll then remove the IV line and needle.
  7. Then, they’ll dress the puncture site on your foot with a bandage.


You may experience a variety of uncomfortable or unpleasant sensations during your leg venogram. These are typically not serious and usually last for only a few minutes.

You may feel pain when the intravenous line is inserted into the vein on your foot, even though the area has been numbed.

In some cases, your doctor might tie a tourniquet around your leg to force the dye into deeper veins. Depending on how tightly the tourniquet is tied, it may cause some discomfort.

Reaction to Contrast Dye

Possible reactions to the contrast dye include:

  • a flushing sensation
  • a brief headache
  • lip or tongue swelling
  • hives or another skin rash
  • nausea
  • vomiting

In rare cases, the contrast material may make you feel itchy, give you hives, or cause difficulty breathing. Tell your doctor if you experience any of these three symptoms. You might be having an allergic reaction.

Other Risks

Tell your doctor if you think you could be pregnant. Any X-ray involves low-level radiation exposure. This isn’t generally dangerous, but it could be an issue for young children or pregnant women.

You might develop an infection at the puncture site on your foot. Your veins may become damaged from the insertion of the catheter.

Other risks include:

  • kidney failure
  • creation or worsening of a blood clot

In very rare cases, an existing blood clot may break loose during the procedure and travel to your lungs. This can cause a pulmonary embolism, which is a blockage of one or more lung arteries.

A normal leg venogram shows your blood flowing freely through the veins in your leg.

An abnormal result shows blockage in one or more of your veins. This blockage may be caused by a blood clot. Other possible causes include a tumor or inflammation.

Your doctor will be able to give you more specific information about any abnormal results on your leg venogram.