How common is CVI?

When something is wrong with your legs, it helps to know you are not the only one. So the natural question about chronic venous insufficiency, often shortened to CVI, is how common it really is.
The number to start with
my.clevelandclinic.org says venous disease in general is very common. As an example, it says varicose veins affect about one in three adults. Take that in slowly. The figure is about varicose veins, which are one kind of venous disease, so read it as a sign that vein trouble is widespread rather than as a count of CVI alone.
What this means for you in plain words
If you have noticed vein symptoms, you are far from alone, since the source calls venous disease very common. This site covers the townships of Frankfort and Rich, and these answers assume little medical background.
Two pages on varicose veins and CVI
For background, the Society of Interventional Radiology has a patient page on superficial venous disease or chronic venous insufficiency. MedlinePlus has a clear page on varicose veins and spider veins. Both are good places to keep reading.
One simple next step
Read the MedlinePlus page first, then jot down any symptom that sounds familiar. A short list helps a clinician, and it helps you remember what to ask.
A closing observation
Commonness means you are not alone with the question. Ask yours without apology, and let a clinician speak to your own case.