removing rings prior to injecting. If a finger starts to swell with a ring in place, it can quickly obstruct the blood flow leading to loss of the finger. The artery that supplies blood to the finger lies just below the vein – if the artery is damaged the finger can die. The superficial veins of the hand tend to‘ wobble’ when people try to get a needle in them, and this can result in more frequent missed hits and vein damage.
Legs
The superficial leg veins are unlikely to be viable long-term prospects for injecting. The blood flow in these veins is slow, and if people inject too quickly there is often leakage into surrounding tissue. This can cause infection and further vein damage or it can cause the person to lose their dose. The legs contain many valves, which increases the likelihood of problems, as injecting at or around a valve causes more turbulence, and therefore clotting of the blood. This can damage the valve and further slow blood flow. The superficial veins of the leg tend to wobble‘ when people try to get a needle in them, and this can result in more frequent missed hits‘ and vein damage. As the flow of blood in the leg veins is upwards( i. e. towards the heart) it can be difficult to self inject in the correct direction in the legs, i. e. with the needle pointing up towards the top of the leg. Because these veins are furthest from the heart, and due to gravity, blood flow through the leg veins is slow. If drugs are injected too fast, the veins will be unable to cope with the extra fluid. When this happens, fluid can escape from the vein, around the needle, causing a miss.‘ Injecting slowly can reduce this. Healing of injection site damage and resistance to infection are less reliable because the blood flow is slow. Abscesses and other infections are therefore more possible for those injecting into their legs.
Varicose veins form, usually in the leg veins, because of damaged valves. The varicose vein has tight, thin walls and is often raised, stretching the skin. They should not be injected into, as they can bleed profusely because the damaged valves mean that blood can run back down the vein and out of the wound.
Feet