What Causes A Prominent And Painful Vein In The Knee?

Brief Answer:
Superficial thrombophlebitis.

Detailed Answer:

Hi, Welcome to HCM
I have gone through your query and reviewed the attached images.
It looks like superficial thromboph;ebitis.

Superficial thrombophlebitis is inflammation of a vein just under the skin, usually in the leg. A small blood clot also commonly forms in the vein, but is usually not serious. The condition usually settles and goes within 2-6 weeks. Treatments can ease pain or discomfort. Superficial thrombophlebitis is different to, and much less serious than, deep vein thrombosis (DVT). However, in a small number of cases, complications can occur with superficial thrombophlebitis, including extension of the blood clot further up the vein. If the clot extends to where the superficial and deep, larger veins join, a DVT can develop.

It is very important to rule out any underlying complications. I suggest you to consult the physician and get physically examined and get any investigations if necessary.

TREATMENT:

Most bouts of superficial thrombophlebitis last for 3-4 weeks. If they are associated with varicose veins, they are likely to return (recur). No treatment may be needed if the symptoms are mild. One or more of the following treatments may be advised, depending on your symptoms and the severity of the condition:

Keep active. Try to keep up your normal activities. This should be possible unless the pain is severe.
A hot cloth (flannel) placed over the vein. This may ease the pain.

Painkilling tablets. Anti-inflammatory painkillers such as ibuprofen may ease the pain (but are not advised if you are pregnant). Paracetamol is an alternative. Some people may not be able to take anti-inflammatory painkillers. Check with your doctor or pharmacist. Always read the packet leaflet that explains possible side-effects. There is also some evidence that anti-inflammatory tablets may reduce the risk of superficial thrombophlebitis enlarging or extending within a vein and/or it coming back. However, more studies are needed to confirm this.
Anti-inflammatory creams or gels. An example is ibuprofen gel. These are an alternative if superficial thrombophlebitis is mild and only affects a small area of vein. They tend to produce fewer side-effects than those taken by mouth.

Hirudoid cream (heparinoid) may improve your symptoms, although there is some evidence that heparin gel may be more effective.

Raising the affected leg. When you rest (when watching TV, or reading a book, etc), if you raise an affected leg so that your foot is higher than your hip, it helps to reduce swelling and discomfort. You can do this by lying on a sofa and putting the leg up on some cushions. When sleeping in bed, you can keep your leg raised by putting it on a pillow.

Compression (support) stockings. These may be advised by your doctor if a vein in your leg is affected. They may ease discomfort and reduce swelling whilst the inflammation settles.

ANY QUERY DO FOLLOW UP.

Take care.

---