Why do I have mild pain in leg vein?

When you mention neck pain for the last 10 days, do you mean a burning sensation in the upper part of your neck? Also, have you felt pins and needles in your left hand and foot? These could be signs of a nerve problem due to the alignment of your neck bones. A medical professional should scan this area to find the exact cause and prescribe the proper treatment, which may include physical therapy or medication if necessary.

Acupuncture helps in opening up the energy level ( commonly referred as 'Qi' in acupuncture theory).
Acupuncture needles are put on various parts of the body which helps in increasing the blood flow.
It has an anti inflammatory effect. It stops body's inflammatory response, increases blood flow and relaxes muscle tone. It helps in flushing out toxins from the body. Acupuncture releases endorphins which are natural hormones to reduce the feeling of pain and puts the patient in ultimate relaxed state i.e feeling of well being.
Electro acupuncture pulsates electric current through the needles.
Such procedure gives quick response and helps in reducing both pain and inflammation in people with arthritis.

A bulging disc pressing against nerves can cause pain and affect your balance. Falling is dangerous. You better go back to the hospital. They might have to change your medicine or try something else. 

You may be suffering from a blood clot in your leg as a result of the accident. Injury to the leg causes blood to pool and form a clot causing swelling, redness, and pain. This is serious because the clot may break free and travel to other parts of your body. Elevate your leg above your heart, apply ice, and take a break. When the pain persists or becomes severe, go to the nearest hospital immediately.