There are many factors that will contribute to how long track marks last. Track marks are formed by an individual who has a drug dependence requiring repeated injections of the drug into a vein or veins. Usually the individual will continue to inject in the same spot over and over then moving along the length of the vein as it becomes difficult to get a hit in the same spot. The vein becomes hardened in each spot where multiple injections have occurred, as this happens the individual will usually move a little bit further down the length of the vain to where it is soft. Each previous spot becomes discolored and scarred. Since the injections have moved along the length of the vein scarring and discoloration occur along the length of the vein causing what is called a track mark.. How long track marks will last depend upon various factors such as, how long an individual continues to use, how healthy the individual is, and many more that we will discuss.
The reason an individual will inject the drug in the first place is mainly because of "First Pass Effect" (also known as first-pass metabolism or presystemic metabolism). This is when the drug bypasses the liver metabolism process that occurs and enters the systemic circulation directly rather than taking a drug orally where it must go through the liver and be processed before entering the systemic circulation causing a loss of some of the drug. therefore when injecting the individual will get more of the drug as well as a "rush" from the drug reaching the systemic circulation all at once. The addiction to the drug is usually physical and mental as well as a mental addiction to the injection process itself.
Blunt Syringes
Through many years of injecting intravenously on a daily basis will cause track marks. One of the variables involved in causing more severe scarring would be repeated injections with the same syringe where the tip has worn down and is blunt. If an individual has access to plenty of syringes and throws away each one after injecting one time would lessen the affect it will have on destroying the tissue and puncturing the vein.
Intravenous Miss
Another factor involved in causing more scarring is when injecting the individual misses the vein. When this happens there is damage that occurs to underlying tissue and vein as it is squeezed by the swelling in the injection site. When there is a miss small blister like bubbles appear around the injection site that become extremely itchy causing the individual to scratch the area thus intensifying more tissue destruction. There are a couple of different ways to inject a drug but these methods will cause bruising of the skin and muscle if done repeatedly everyday in the same area. the two methods are: "skin popping" (this where the syringe is placed just under the skin and injecting, not in a vein - this can cause abscesses) and "intramuscular injecting" (this is where the syringe is placed right into the muscle and injected - this can cause bruising of the skin and hardened muscles). Usually these methods are not used by addicted individuals because mainly it takes a bit of time to reach the systemic circulation where intravenous injections are direct and produce a much more intense high.
Hitting The Same Vein
When a user is injecting daily it is common to return to the same spot and vein since the individual knows they can get a sure hit. Using a different vein or spot can sometime be difficult to get a hit and misses happen at a higher rate. When a miss occurs the intense high is not met and there is a sense of failure just as if the individual may have spilled the drug on the floor. For this reason it is common for the individual to continue hitting the same spot where they will feel secure knowing they can get a hit into the vein without a problem. However, if the individual has prominent veins and a new syringe hitting a different vein and spot all of the time will minimize track marks. It is all of these things that will determine how long track marks will last. when enough scaring has occurred the track marks may last forever or may require some plastic surgery to reduce the way they look.