Collapsed veins are usually the result of chronic use of intravenous injections. If this is what you are referring to, then the condition is irreversible. Collapsed veins cannot be rejuvenated or fixed in any way.
Occasionally, veins can get temporarily blocked due to injury or irritation. This is a relatively harmless condition, and once the swelling subsides, the blockage clears and circulation returns to normal.
However, regular use of intravenous injections can damage vein lining, both by tearing it and due to irritation caused by the injected drugs. The vein lining begins to swell, and tiny clots begin to form on it. Eventually, the swelling and clots can block the vein, ultimately resulting in collapse. The condition can be quite painful. After the collapse of a vein, blood flow is redirected to other blood vessels, usually smaller or deeper veins. These do not have the same capacity as the collapsed vein, due to which they begin to swell up, in turn causing swelling of the affected limb as well. Due to the resultant poor circulation, minor cuts and bruises as well as puncture wounds from subsequent injections become painful and heal slowly. If you experience these symptoms, you should seek help from your doctor.
answered by G M