Section 5: Vein and other local damage

Vein blockage and collapse
Deep vein thrombosis (DVT)
Long-term consequences of vein collapse
Factors affecting healing
'Missed hits'
'Lumps and bumps'
Key points


This section looks at damage to veins and infections of injecting sites. Vein blockage is discussed, as are the consequences of poor circulation such as ulcer formation.

Evidence suggests that most injectors experience at least some of these complications and tend not to access appropriate treatment for them unless or until they have reached crisis point. This is likely to result in greater levels of permanent damage and the client requiring much more intensive and expensive treatment.98

It would be desirable to have staff with nursing and medical expertise available within all syringe exchanges. However, in reality this is not possible for many services. Some drug services have few, if any staff with a medical or nursing background.

Vein blockage and collapse
Figure 5.1: Collapsing and collapsed vein

Adapted from The Safer Injecting Handbook, Andrew Preston and Jon Derricott, 1998, ISDD

Veins may become temporarily blocked if the internal lining of the vein swells in response to repeated injury or irritation. This may be caused by the needle, the substance injected, or both. Once the swelling subsides the circulation will often become re-established.

Permanent vein collapse (see Figure 5.1); occurs as a consequence of:

bult57[1].gif (589 bytes) Long-term injecting

bult57[1].gif (589 bytes) Repeated injections, especially with blunt needles

bult57[1].gif (589 bytes) Poor technique

bult57[1].gif (589 bytes) Injection of substances which irritate the veins.

Smaller veins may collapse as a consequence of too much suction being used when pulling back against the plunger of the syringe to check that the needle is in the vein. This will pull the sides of the vein together and, especially if they are inflamed, they may stick together causing the vein to block. Removing the needle too quickly after injecting can have a similar effect.


If the smooth blood flow through the vein is disrupted, clots can form on the lining of the vein. This process is called thrombosis. Over time, continuing to inject and the clots themselves will encourage further clotting. Eventually the vein can become completely blocked by the clot.

Wherever blood clots in a vein (or elsewhere) it will eventually be transformed into scar tissue. Scar tissue forms to pull the edges of a wound together ­ when it occurs on the inside of a vein the contraction leads to narrowing and blockage of the vein. Following this process the vein appears to collapse (Figure 5.1).

A vein that is filled with scar tissue seldom recovers its ability to carry blood.

Collateral circulation

When a vein becomes thrombosed or obstructed, blood can no longer flow through it to return to the heart. The blood will therefore take an alternative route, using other smaller blood vessels to get around the blockage. This diversionary circulatory route is called 'collateral circulation'.

This process may result in the appearance of 'new' superficial veins on or near the skin surface. Injectors should be discouraged from attempting to use these veins, as they are likely to be small veins that have become engorged by the necessity for them to carry more blood. They will therefore be under greater pressure than normal, so that injecting into them carries a greater risk of damage to the vein.

The usual consequence of injecting into such veins is that within a few injections the vein becomes damaged and is no longer viable.

If the collateral circulation becomes damaged, then the return of venous blood from the affected limb is likely to be even more severely restricted.

Deep vein thrombosis (DVT)

A DVT is a clot which completely or partially blocks a deep vein. Initially the clot consists of dense layers of platelets and fibrin; later it becomes a jelly-like mass of fibrin and red cells which may detach to form an embolus. This may result in a pulmonary embolism (see page 90).

The most common site for a DVT is in the lower limbs, usually in the deep veins at the back of the calf (Figure 5.2). More rarely, it can also occur in the arms.

The range of symptoms that can be produced by a DVT is wide, from no obvious ones at all to tissue breakdown and ulcer formation.

Symptoms of the presence of a DVT can include:

bult57[1].gif (589 bytes) Pain (usually in the back of the calf)

bult57[1].gif (589 bytes) Oedema (swelling) of the affected limb

bult57[1].gif (589 bytes) Cyanosis of the limb (bluish discoloration indicating impaired blood supply)

bult57[1].gif (589 bytes) Pulmonary embolism.

A DVT which is not treated can, over time, cause a condition called post-phlebitic syndrome. The blockage of the vein and the destruction of valves leads to raised pressure in the remaining veins which may lead to:

bult57[1].gif (589 bytes) Chronic pain

bult57[1].gif (589 bytes) Oedema

bult57[1].gif (589 bytes) Eczema

bult57[1].gif (589 bytes) Ulceration.

A number of factors can increase the risk of a DVT. These include:

bult57[1].gif (589 bytes) Femoral 'groin' injecting

bult57[1].gif (589 bytes) Obesity

bult57[1].gif (589 bytes) Smoking

bult57[1].gif (589 bytes) Pregnancy

bult57[1].gif (589 bytes) Contraceptive pill

bult57[1].gif (589 bytes) Lack of exercise

bult57[1].gif (589 bytes) Recent surgery (particularly abdominal).

Treatment of a DVT

If you suspect that a client has a DVT, they should be referred for urgent medical advice.

Immediate treatment may include:

bult57[1].gif (589 bytes) Hospitalisation ­ for X-ray and other screening

bult57[1].gif (589 bytes) Bed rest

bult57[1].gif (589 bytes) Raising the affected leg above the level of the heart when seated or lying down, in order to encourage venous return

bult57[1].gif (589 bytes) Discouraging exercise ­ this could lead to part of the clot breaking off and causing a pulmonary embolus

bult57[1].gif (589 bytes) Anticoagulant (blood thinning) therapy with heparin to dissolve the clot.

Figure 5.2: Position of a DVT and route to pulmonary embolus


For up to three months following discharge, warfarin treatment (an oral alternative to heparin) may be prescribed and closely monitored to prevent recurrence. Injecting should be discourged if anticoagulant treatment is taking place, as the likelihood of direct complications related to slower blood clotting is raised.

Avoidance of a DVT

For those who are at risk of a DVT, or have already experienced it, the possibility of further problems may be reduced if they are encouraged to:

bult57[1].gif (589 bytes) Appreciate practices which increase the risk of a DVT, such as femoral injecting

bult57[1].gif (589 bytes) Identify ways of reducing the risk of developing a DVT, such as changing injecting sites or method of using drugs

bult57[1].gif (589 bytes) Change their route of administration to one that does not involve injecting.

Long-term consequences of vein collapse

When the flow of blood through the limbs has been severly affected, there are a number of problems that can arise. These include:

bult57[1].gif (589 bytes) Ulcers

bult57[1].gif (589 bytes) Gangrene

bult57[1].gif (589 bytes) Local infection.

They are now discussed in detail.


Figure 5.3: Cross-section of an ulcer

Severely reduced flow of blood through the tissues leaves them vulnerable to infection and with a reduced healing capacity.

The result of this process can be that painful areas of broken skin known as ulcers often form (Figure 5.3) following progressive damage to the veins from repeated and inexpert injecting.

Once localised damage has occurred, the impaired venous return in the area, coupled with the fact that blood flow in the lower legs is slow, combines to make prompt healing of an injury less likely than it otherwise would be. This can then be compounded by infection.

Ulcers can form either as the direct result of an injecting injury, or as a result of accidental injury after the veins have been damaged by injecting.

Factors affecting healing

Factors which may affect healing of injecting injuries include:

bult57[1].gif (589 bytes) Diet and nutrition

bult57[1].gif (589 bytes) Stress

bult57[1].gif (589 bytes) Poor accommodation

bult57[1].gif (589 bytes) Drug and alcohol use.

Treatment of ulcers

Unless a project is specifically set up to provide primary health care to clients, the client should be referred to either their general practitioner or an A&E department for assessment and treatment.

Ulcers take many months to heal and may require frequent attendance for treatment.

There are strong arguments for advocating that these and other health care needs will best be met within drug treatment and needle exchange services, because:

bult57[1].gif (589 bytes) Users of drug treatment agencies may not attend if referred to other agencies

bult57[1].gif (589 bytes) Drug users may tend to believe health problems are to be expected and therefore do little about them

bult57[1].gif (589 bytes) They are less likely to receive discriminatory treatment.

Local infections

As well as risks of systemic infections such as hepatitis and HIV, injecting carries the risk of introducing bacterial and fungal infections to the tissue surrounding the injection site. Often local infections are caused by bacteria which live harmlessly on the skin being picked up by the needle and forced below the skin where they multiply.

The risks of local infection will be increased by:

bult57[1].gif (589 bytes) Sharing of needles and syringes

bult57[1].gif (589 bytes) Reuse of unsterile equipment

bult57[1].gif (589 bytes) Sharing of paraphernalia

bult57[1].gif (589 bytes) The use of contaminated equipment in the sharing of drugs

bult57[1].gif (589 bytes) The use of non-pharmaceutical medication

bult57[1].gif (589 bytes) Unhygienic preparation of drugs

bult57[1].gif (589 bytes) Poor personal hygiene.

Providing injectors with an understanding of the ways in which infection may be introduced is crucial. Ideally, they should be aware of the risks they may be exposed to and how to reduce them.

Beneficial actions which can be taken by injectors range from the simple but effective, such as hand washing prior to injecting99 (where adequate facilities are available), to an elaborate aseptic ('germ free') injecting technique. Local infections include:

bult57[1].gif (589 bytes) Abscesses

bult57[1].gif (589 bytes) Ulcers

bult57[1].gif (589 bytes) Cellulitis.

These are now discussed in detail.


An infected abscess is a localised collection of pus that is encapsulated within inflamed tissue (Figure 5.4). It can be caused by a wide range of bacterial and fungal infections.

An abscess is different from cellulitis in that it has a defined edge and shape.

Figure 5.4: Abscess

An abscess is characterised by:

bult57[1].gif (589 bytes) Raised skin surface

bult57[1].gif (589 bytes) Localised heat

bult57[1].gif (589 bytes) Tenderness and pain

bult57[1].gif (589 bytes) Redness of the skin (in white people)

bult57[1].gif (589 bytes) Pus formation

bult57[1].gif (589 bytes) A foul smell if it has begun to discharge.

People with abscesses should be referred for medical advice and treatment. The abscess will require antibiotic treatment and/or lancing to release the pus.

Injectors should be told never to try to lance or puncture abscesses themselves. This can spread infection and without appropriate antibiotic cover they can quickly develop septicaemia (blood poisoning). They should be encouraged to alternate injecting sites as this will lessen the risk of localised inflammation, infection and abscess formation.


Phlebitis is irritation of the smooth inner lining of a vein (tunica intima). The roughening of the vein lining can encourage the formation of clots. The vein is reddened or inflamed and can sometimes be felt as a thick cord beneath the skin.

Phlebitis can occur as a result of:

bult57[1].gif (589 bytes) Injecting irritant substances such as Temazepam

bult57[1].gif (589 bytes) Poor injecting technique

bult57[1].gif (589 bytes) Infection

bult57[1].gif (589 bytes) Accidental injury (i.e. knocks or blows).

An important complication of phlebitis is deep vein thrombosis leading to pulmonary embolism.

If phlebitis is suspected the person should be referred for immediate medical advice. Treatment includes resting and raising the affected limb, antibiotics and anti-inflammatory drugs.


Cellulitis refers to a painful spreading inflammation of the skin, which appears red and swollen with fluid (this is known as oedema).

Cellulitis can occur as a result of:

bult57[1].gif (589 bytes) Irritant substances lodged in body tissues

bult57[1].gif (589 bytes) Infection.

It is usually the result of a 'missed hit' and/or poor circulation.

Where cellulitis is suspected the client should be referred for immediate medical advice. Treatment includes resting and raising the affected limb, and treatment with antibiotics and anti-inflammatory drugs.

Advice for people who have had cellulitis would include the following measures to prevent reinfection:

bult57[1].gif (589 bytes) Using sterile injecting equipment

bult57[1].gif (589 bytes) Using sterile water where available and discussing alternatives where it is not

bult57[1].gif (589 bytes) Avoiding the injection of irritant or heavily adulterated drugs

bult57[1].gif (589 bytes) Removing rings prior to injecting if injecting in the hands.

'Missed hits'

Figure 5.5: 'Missed hits'

'Missed hit' is a phrase used to describe swelling which appears around an injection site during or immediately after injection.

It may be caused by fluid entering the tissue surrounding the vein because the needle has:

bult57[1].gif (589 bytes) Not entered the vein properly

bult57[1].gif (589 bytes) Entered the vein and slipped out again

bult57[1].gif (589 bytes) Entered the vein and gone through the opposite wall

bult57[1].gif (589 bytes) Entered the vein correctly but excess pressure caused the vein to split.

These problems can be prevented by encouraging injectors to:

bult57[1].gif (589 bytes) Check that the needle is in a vein by gently pulling back on the plunger to see that venous blood enters the syringe

bult57[1].gif (589 bytes) Always releasing the tourniquet before injecting

bult57[1].gif (589 bytes) Maintain a steady hand whilst injecting

bult57[1].gif (589 bytes) Smoke a small amount of heroin before injecting, when in opiate withdrawal

bult57[1].gif (589 bytes) Use the smallest possible needle and syringe barrel

bult57[1].gif (589 bytes) Inject at the correct angle

bult57[1].gif (589 bytes) Inject the fluid slowly.

A missed hit will mean that the drug is absorbed much more slowly by the body, so that the effect will be less pronounced. It can also lead to other problems discussed in this section such as:

bult57[1].gif (589 bytes) Abscesses

bult57[1].gif (589 bytes) Cellulitis

bult57[1].gif (589 bytes) Cutaneous foreign body granulomas.

'Lumps and bumps'

Injectors often have various 'lumps and bumps' on their skin. These have differing causes.

Blocked veins can leave hard 'knots' under the surface of the skin. Developing abscesses may first appear as a raised bump, although this is often accompanied by localised tenderness and heat. Other possible causes of 'lumps and bumps' are detailed here.

Sterile abscess

A sterile abscess occurs as a result of injecting irritant substances such as crushed tablets and possibly as a consequence of a missed hit. It will often disperse without treatment but, over time, a granuloma may form around it.

Cutaneous foreign body granulomas

Granulomas are benign growths of scar tissue that are associated primarily with subcutaneous injecting or 'missed hits', where the solution has by accident or design ended up in the surrounding tissue. In such cases a residue may stay for many years, eventually leading to granuloma formation100.

Many of the common cutting agents for injectable drugs, such as quinine, mannitol, dextrose and lactose, are not thought to cause foreign body granulomas. However the injection of crushed tablets will increase the risk. The principle filler of the tablet is often hydrogenous magnesium silicate, frequently referred to as 'chalk' by users.

It should be noted that 'successful' intravenous injection of crushed tablets does not remove the risk of granuloma formation. It simply changes the place that they may be found, to the lungs.

In Australia, attempts have been made to supply tablet injectors with commercially produced filters (Millipore filters) which are intended to remove the chalk from the solution. If beneficial and practical (they are relatively expensive), then this may be a rare example of a successful harm reduction strategy for those injecting tablets. However, there is the potentially much greater problem of transmission of blood-borne viruses if these filters are reused or shared.

Because of this, the best harm reduction intervention is likely to remain clear advice not to inject crushed tablets.


Gangrene is the death of body tissues caused by impaired or absent blood supply. Gangrene can occur as a result of arterial or serious venous damage.

The effect of gangrene can be disastrous, leading to loss of limbs. It can also cause the products of tissue breakdown to enter the bloodstream causing blood poisoning and threatening life.

Arterial damage

Gangrene as a result of arterial damage occurs when an artery is injected into instead of a vein. Often this is as a result of injecting irritant drugs such as Temazepam into the femoral artery rather than the femoral vein. However, it can occur when people inject into the smaller arteries in the arm.

Gangrene as a result of injecting into an artery can occur in the following ways:

bult57[1].gif (589 bytes) The artery can go into spasm and interrupt the supply of oxygenated blood to the tissues

bult57[1].gif (589 bytes) The injected substance can block the artery, interrupting the blood supply to the tissues

bult57[1].gif (589 bytes) Small particles of the injected substance (micro-emboli) can be transported into and block the capillaries in the tissue ­ causing their breakdown.

Venous damage

Gangrene following venous damage may be slower to develop, and results when damage to the veins is such that the return of venous blood from the affected limb is no longer adequate; blood gets into the tissues at a faster rate than it can get out. In the end the reduced flow of blood through the tissues is inadequate to sustain them and they die.

Signs and symptoms

Signs and symptoms of gangrene include:

bult57[1].gif (589 bytes) Pain

bult57[1].gif (589 bytes) Loss of feeling and control in an area of skin

bult57[1].gif (589 bytes) Swelling and discolouration of affected limb

bult57[1].gif (589 bytes) Affected extremities i.e. fingers or toes

bult57[1].gif (589 bytes) Affected tissues initially becoming white

bult57[1].gif (589 bytes) Affected tissues eventually blackening

bult57[1].gif (589 bytes) If untreated, affected tissues dropping off.

Prevention and treatment

Injecting drug users need to be given advice on the following subjects to enable them to prevent gangrene occurring:

bult57[1].gif (589 bytes) The dangers of arterial injection

bult57[1].gif (589 bytes) The signs and symptoms of injecting into arteries

bult57[1].gif (589 bytes) First aid treatment following accidental arterial injection

bult57[1].gif (589 bytes) Discourage injection of crushed tablets especially Temazepam tablets, Temazepam Gelthix capsules and Diconal.

In the event of symptoms of gangrene occurring injectors must be aware that:

bult57[1].gif (589 bytes) This is a serious complication that will not go away unless they get medical help

bult57[1].gif (589 bytes) They must get urgent medical treatment ­ if the onset is sudden they should call an ambulance.

Key points

bult57[1].gif (589 bytes) Irritation and infection can cause veins to block temporarily.

bult57[1].gif (589 bytes) Vein collapse occurs as a consequence of long-term injecting. Repeated injections, especially with blunt needles, poor technique and of substances which irritate the veins, encourage vein collapse.

bult57[1].gif (589 bytes) Permanent vein blockage results from the formation of scar tissue in the vein, following blood clotting.

bult57[1].gif (589 bytes) Severely reduced flow of blood through the tissues leave them vulnerable to infection and with reduced healing capacity.

bult57[1].gif (589 bytes) All drug injectors should be warned that they should never inject into a blood vessel in which they can feel a pulse.

bult57[1].gif (589 bytes) Injecting in the hands and fingers should be discouraged ­ those who insist on these sites should be warned to remove rings prior to injecting.

bult57[1].gif (589 bytes) Injectors should be warned of the symptoms of gangrene and advised to seek urgent medical advice if they suspect that it may be occurring.

bult57[1].gif (589 bytes) If in any doubt, get medical advice immediately.

©Jon Derricott
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