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Avoiding Arteries (Part 2)

In the last article in this two part series, we discussed the differences between veins and arteries and how to avoid the dangerous and painful act of injecting into an artery. Regardless of the precautions taken, however, sometimes, users inject into arteries. In this article, we discuss what to do when a user injects into an artery.

Red glowing hand. How Arteries Work

Oxygen and nutrients are transported to the various parts of the body through blood delivered by the arteries. The blood moves from large arteries to progressively smaller arteries--called arterioles. Eventually, the oxygen and nutrients in the blood end up in capillaries where they are absorbed by the tissue.

Blood Absorption by Tissue

The oxygen and nutrients in blood are transported across the capillary walls into the tissue. Because of the volume of blood that must be moved around, there needs to be a large area of capillary wall. This is accomplished by having a lot of capillaries, because any given capillary is extremely small--about 0.025 inches long (the width of perhaps ten strands of hair) and 0.0005 inches in diameter (this can't even be seen by the naked eye). But because of the enormous number of capillaries, the total area of capillary walls in the body is large--about 5000 square feet--that's the size of two fairly large houses.

Heroin in Arteries

When heroin is injected into an artery, it is treated just like blood--each molecule is transported to a capillary where it can be absorbed by the tissue. The chemical reactions that occur hurt the tissue and cause pain.

One doctor I spoke to indicated that another reason for the pain from injecting heroin into an artery was that the arteries themselves had a large number of pain receptors compared to veins. I have not found corroboration for this theory, however.

The biggest long-term concern about injecting heroin into an artery, is that blood clots may form. Blood clots can stop the flow of oxygen to near-by tissue--causing the tissue to suffocate and die. In addition, pieces of a blood clot can break off and lodge in another location--in some cases, they can lodge in a more dangerous location like the brain, causing a stroke.

Threat to Life

Rarely, an arterial injection may pose a threat to the user's life. In most of these cases, this will not happen right when the injection is made--as when a blood clot breaks away from a limb, for example, and gets caught in the brain. In some cases, however, there will be an immediate threat to life.

If an injection causes such a threat--causing the user to be unable to breath, for example--medical attention should be sought immediately. Call 911 or go to a hospital, whatever makes the most sense.

An Ounce of Prevention

The only way to assure that a user will not inject into an artery, is to not inject drugs at all. The fact of the matter is that if a user injects enough times, he will eventually inject into an artery. It is only a matter of time because there is no iron clad method of differentiating between veins and arteries.

But by taking the proper precautions, users can greatly reduce the risk that any given injection will be into an artery. For example, one user I talked to had a five year run of daily using; he injected into an artery only once. That represents between 5,000 and 10,000 injections. This is a pretty good track record and it comes from following the advice found in the first article in this series.


Although it is not common, and it is a problem with injections of all kinds, not just arteries, the tissue affected can become infected. As with any injection, great care must be taken to assure that the needle, hands, and injection area are clean. In addition, the user should try to administer heroin in clean surroundings. For example, avoid dirty places like public rest rooms and dusty places like barns.

Short-Term Care

When heroin is injected into an artery, it follows the same path to tissue that blood does. Of course, the last thing a user wants is for the heroin to do this because it is painful, wasteful, and damaging to the body. When this happens, the user should slow the blood flow as much as possible, in order to limit the area with which the heroin interacts.


The moment you determine that you have injected into an artery, you should stop. If you have not flushed all of the contents of the syringe, stop flushing the syringe and remove it from the injection site. The less that is injected into the artery, the less damage will be done.

Ice It!

As soon as possible, the injection area should be iced. Since this limits the area to which heroin spreads, it will also limit the swelling of the tissue and the amount of tissue that is damaged.

Massage It!

Massaging the area that has been affected also can be helpful. This encourages the flow of toxins out of the tissue. The user must be careful, however. This should only be done as much and as intensely as is comfortable. It is possible to do further damage to the tissue. Don't follow the philosophy, "No pain, no gain"!

Long-Term Care

After 24 hours, the swelling of affected area should have gone down substantially. It should be within 90% of normal. Even though the area will look much better, the user should still monitor it and treat it until the area is completely normal.

Ice? Heat?

Professional opinions differ regarding the long-term care of the swollen tissue from an arterial injection. Some say that the patient should continue to apply ice to the area. Others say that the patient should apply heat to the area. Still others say that the patient should alternate applications of heat and ice. All sources agree, however, that ice should be applied for the first 24 hours.


Massaging can also be used in the days following the arterial injection. The same precautions taken immediately following the injections should be taken later.


One thing should definitely be done: keep the area clean. How often the sufferer cleans the area will depend upon his environment and activities. It should be done at least once a day. This should be done gently with soap and water, under most circumstances.

If the wound is opened--this is called a fistula and is normally a sign of an infection--it should be rinsed with hydrogen peroxide. Sterile syringes work very well for this purpose.

Medical Attention

If after 24 hours, the swelling has not reduced substantially or it is still quite painful, the user should seek medical attention. The body responds quickly to a normal arterial injection. If it has not repaired itself within a day, it means something more is wrong that should be investigated.


If an IV injector uses long enough, he will eventually inject into an artery. This is simply a risk that anyone who injects drugs into his veins must accept. Knowing this, he should prepare for this event and think through what to do after an arterial injection.

by Dr. H © 2001
Last Modified: 9 January 2004