Possible Complications and How to Prevent Them

The Spectrum of Complications: Mild to Severe

In one line

Most complications are common, mild, and resolve on their own (bruising, swelling). Severe complications (vascular occlusion) are rare but require knowledge, equipment, and immediate access to treatment. The choice of an experienced practitioner is the most significant factor in reducing risk.

It is important to distinguish between side effects — which are an expected and normal part of the treatment — and complications — which are undesired outcomes that require intervention. A further distinction: early complications (hours to days after treatment) vs. late complications (weeks to months).

Common and Expected Side Effects

These are not complications — they are a normal part of the process:

Swelling — almost always. Lasts 2–7 days. In lips — significant swelling in the first 48 hours. In other areas — milder.
Redness — at the injection site. Lasts hours to a day or two. Normal.
Tenderness and discomfort — the area is sensitive to touch for several days. Does not require treatment beyond standard pain relievers.
Bruising (ecchymosis) — common, especially in areas with rich vascular supply (lips, under the eyes). Resolves over 7–14 days. Using a cannula reduces the likelihood.

Our guidance: do not take aspirin or ibuprofen in the week before treatment (they increase bruising risk), avoid alcohol 24 hours before, and avoid intense physical activity 24–48 hours after.

Vascular Occlusion — The Most Serious Complication

Especially important

Vascular occlusion is the most serious complication of filler injection. It is rare (estimates: 1 in 10,000 to 1 in 100,000 treatments), but when it occurs — it requires immediate treatment to prevent tissue necrosis. In the most severe cases, if filler reaches the artery that supplies the retina — there is a risk of loss of vision.

How It Happens

Two mechanisms:

Direct occlusion (intravascular injection) — the needle enters a blood vessel and filler is injected directly into the bloodstream. The filler lodges and occludes the vessel.
External compression (extravascular) — a large amount of filler injected outside the vessel presses on it and blocks flow.

Early Signs

Blanching of the skin in the area — the area suddenly turns white
Unusual pain not proportional to the treatment
A purple-bluish (livedo) discoloration that appears and spreads
Visual disturbance (in cases involving orbital vessels) — blurring, double vision, loss of visual field

Immediate Treatment

If vascular occlusion is suspected — treatment begins immediately, at that moment:

Injection of hyaluronidase in a large amount into the area — breaks down the HA and thereby releases the occlusion
Warm massage of the area to encourage flow
Topical nitroglycerin to dilate blood vessels
Close monitoring in the following hours
In cases with orbital involvement — immediate referral to an ophthalmologist

For this reason — any practitioner who injects fillers must keep hyaluronidase in the clinic, know how to identify vascular occlusion, and know how to treat it. This is not theoretical — it is a basic safety requirement.

Other Complications

Complication	Frequency	Mechanism	Prevention and treatment
Tyndall effect	Moderate (under the eyes)	HA placed too superficially scatters blue light	Injection at sufficient depth; dissolving if it occurs
Lumps and irregularity	Common (mild)	Uneven injection, filler that does not disperse	Early massage, targeted dissolving, sometimes resolves on its own
Asymmetry	Common (mild)	Uneven injection, asymmetric swelling, uneven absorption	Correction via touch-up after 2 weeks
Migration	Low-moderate	Filler shifts from the injection site — especially soft HA in high-movement areas	Appropriate product selection, correct technique; dissolving if significant
Infection	Rare	Bacterial entry through injection points	Strict antisepsis, sterile technique; antibiotics if it occurs
Granuloma	Rare (0.01–0.1%)	Late inflammatory reaction — the body "attacks" the filler	Topical steroids, hyaluronidase; sometimes requires prolonged treatment
Biofilm	Very rare	Bacteria that colonize the surface of the filler and form a protective layer	Prolonged antibiotics, filler dissolving; sometimes surgical drainage

How Risk Is Minimized

Risk cannot be eliminated entirely — every injection carries minimal risk. But it can be reduced significantly:

On the Practitioner's Side

Deep anatomical knowledge — knowing the mapping of blood vessels, tissue layers, and danger zones. This is the most meaningful difference.
Use of a cannula — in appropriate areas. A cannula (rounded tip) pushes blood vessels aside rather than piercing them. Reduces vascular risk and bruising.
Slow injection — low injection pressure reduces the risk of external compression of vessels and allows early signs to be noticed.
Aspiration — pulling back on the plunger before injection to verify the needle is not inside a vessel. Not always possible with every product, but when possible — worthwhile.
Measured amounts — less material = less risk. A conservative approach with the option of a touch-up is preferable to trying to "do everything in one session."
Immediate access to hyaluronidase — mandatory in every clinic that injects fillers. Not in a cabinet in the back room — next to the treatment chair.

On the Patient's Side

Report previous filler treatments — including what, where and when
Stop blood thinners (if medically possible) a week before
Do not treat when there is an active infection in the area (herpes, inflammatory acne)
Contact the practitioner immediately if there are unusual signs after treatment — severe pain, blanching, changes in vision

Our approach

We talk about complications before the treatment — not to frighten, but because real informed consent requires that the patient know what the risks are. A patient who understands the risk makes an informed decision. It is part of the process, not an obstacle.

Frequently Asked Questions

What are the chances that something will go unplanned?

Mild side effects (swelling, bruising, mild asymmetry) — common, in the tens of percent. Meaningful complications requiring intervention — rare, in fractions of a percent. Severe complications (vascular occlusion) — very rare, 1:10,000 or less. But "rare" does not mean "impossible," which is why preparation matters.

How do I know my practitioner is prepared for complications?

Ask: is there hyaluronidase in the clinic? Do you know how to treat vascular occlusion? A practitioner who struggles to answer, or who dismisses the question — that is a concerning sign. A professional practitioner will be happy to discuss it because it is part of their professionalism.

What should I do if I suspect something is not right after treatment?

Contact the practitioner immediately. Do not "wait and see" — especially if there is unusual pain, blanching of the skin, or a change in vision. These are signs that require immediate evaluation. Swelling, tenderness and bruising — normal. Sharp pain or a sharp color change — not.