Quick answer: To recognize filler complications, know the difference between normal and warning signs. Mild swelling, tenderness and small bruises are normal. Severe or increasing pain, skin that turns pale, blue, grey or blotchy, blisters, or any change in vision are warning signs of a vascular complication and need urgent medical help. Signs of infection or lasting lumps also need a doctor's review.
Key takeaways
- Mild swelling, bruising and tenderness are expected after filler.
- Severe pain and skin colour changes can signal blocked blood flow.
- Any vision change after filler is a medical emergency.
- Infection, lasting lumps and delayed swelling also need review.
- Hyaluronic acid filler can be dissolved, and early treatment matters.
Why understanding complications matters
Dermal fillers, most often made of hyaluronic acid, are widely used and generally safe when performed by trained doctors. However, like any medical procedure, complications can occur. Most are minor and temporary, but a small number need prompt treatment. Knowing what is normal and what is not helps you act quickly if something unusual happens.
What is normal after filler?
- Swelling: peaks in the first one to two days and settles within one to two weeks.
- Bruising: small bruises that fade over a week or so.
- Tenderness: mild soreness when touching the area.
- Slight firmness or unevenness: often improves as swelling settles.
Warning signs of a vascular complication
A vascular complication happens when filler blocks or presses on a blood vessel, reducing blood flow to the skin. It is rare but serious. Warning signs include:
- Severe pain that is out of proportion or keeps increasing.
- Skin that turns pale or white, then dusky, blue, grey or mottled.
- Slow return of colour when you gently press the skin.
- Blisters, scabs or dark patches in the days after treatment.
- Any change in vision, such as blurring or loss of sight.
If you notice these signs, contact your clinic immediately or seek emergency care. Hyaluronic acid filler can be dissolved with hyaluronidase, and early treatment gives the best outcome. Vision changes require emergency treatment without delay.
Signs of infection
- Increasing redness, warmth or swelling after the first few days.
- Pain that worsens rather than improves.
- Discharge or pus from injection points.
- Fever or feeling unwell.
Infections usually respond to treatment, but they should be checked promptly by a doctor.
Lumps, nodules and delayed swelling
Small lumps may be felt early and often smooth out. Lumps that persist beyond a few weeks, become painful, or appear months later should be reviewed. Delayed swelling can sometimes occur weeks or months after filler, for example after an illness. Your doctor can assess and treat these, sometimes by dissolving the filler.
Other possible issues
- Tyndall effect: a bluish tint when filler is placed too shallow, often under the eyes.
- Migration: filler appearing outside the intended area.
- Asymmetry: uneven results that remain after swelling settles.
- Allergic reactions: rare, but need medical review.
How to reduce your risk
- Choose a qualified doctor with strong knowledge of facial anatomy.
- Make sure the clinic uses genuine, approved filler and keeps hyaluronidase available.
- Ask about the product, amount and technique, needle or cannula.
- Follow aftercare instructions and avoid pressure on the area.
- Keep your clinic's contact details and know how to reach them after treatment.
What to do if you are travelling
Korea treated about 2.01 million foreign patients in 2025, and around 63% came for dermatology, according to the Ministry of Health and Welfare. If you have filler in Seoul, stay nearby for at least a day or two if possible, keep your clinic's contact details, and take photos of the area. If a warning sign appears after you fly home, seek urgent care locally and tell the doctor which filler was used.
Frequently asked questions
Is bruising after filler a complication?
Usually not. Small bruises are common and fade within about a week.
How quickly do vascular complications appear?
Often during or soon after treatment, but signs can develop over hours or days.
Can complications be treated?
Yes. Many can be treated, especially when recognized early.
Should I contact my clinic if I am unsure?
Yes. It is always better to check than to wait.
Sources
- Ministry of Health and Welfare, Republic of Korea – 2025 foreign patient statistics (press release, 2026).
- U.S. Food and Drug Administration – dermal filler safety communication.
- Ministry of Food and Drug Safety, Republic of Korea – medical device approval information (dermal fillers).
This article is for general information only and is not medical advice. Results vary between individuals. Please consult a qualified physician before any treatment.
