In short. Irregularity is the commonest problem and the one patients regret most. Fat dies and forms a cyst, what can be corrected, and the risks that change consent.
Key points
- There is no dissolving agent for fat.
- A lump that persists can be treated by surgical removal or by adding small volumes of fat around it to blend the contour, but neither is as controllable as dissolving a filler.
- This is the practical reason the area-by-area reliability of fat transfer matters so much: the places where it is least predictable are also the places where correction is hardest.
The complication patients most often regret is not the dramatic one. It is irregularity: a lump, an unevenness, a surface that looks bumpy in certain light. That is the risk to weigh most carefully, because it is the most common, the most visible and sometimes the hardest to correct.
Why lumps form
Fat needs a blood supply to survive in its new position. Placed in parcels small enough to be reached by new vessels, it takes. Placed in a deposit too large to be reached, the cells at the centre die, and dead fat is replaced by oil and scar tissue. That can present as an oil cyst, a firm area, or a persistent irregularity. Placement technique is the main defence: many small passes in several tissue planes rather than a few large deposits.
Under-correction and over-correction
Under-correction is not a complication in the surgical sense, but it is the commonest reason patients are unhappy, because less fat survived than was hoped. Over-correction leaves the face looking filled or heavy, and unlike filler it cannot be dissolved. Both are managed by a second procedure at the appropriate time, which is one reason the timing of a revision matters so much.
Why irregularity is harder to fix than to avoid
There is no dissolving agent for fat. A lump that persists can be treated by surgical removal or by adding small volumes of fat around it to blend the contour, but neither is as controllable as dissolving a filler. This is the practical reason the area-by-area reliability of fat transfer matters so much: the places where it is least predictable are also the places where correction is hardest.
Infection, bleeding and the donor site
Infection is uncommon and usually treatable, occasionally requiring drainage. Bleeding and bruising occur at both the donor and recipient sites, and a collection of blood may need attention. The donor site carries its own risks: prolonged soreness, numbness, contour irregularity where fat was taken, and a permanent scar. These are usually minor but are frequently underestimated before surgery.
The rare risks that belong in consent
Injury to structures near the injection site and embolic complications are rare but serious, and they are why the depth of injection and the volume placed at each pass matter more than the total volume. General anaesthetic risks apply where sedation or anaesthesia is used, and a hospital setting manages them without removing them. Any consent conversation that mentions only lumps is incomplete.
Seek care rather than waiting
- Rapidly increasing swelling, a tense painful area, or bleeding that will not stop with pressure.
- Spreading redness, warmth, fever above 38 °C, or discharge from an incision.
- A lump that is painful, hot or growing, rather than one that is softening over months.
Which areas carry the highest risk of irregularity is set out under where fat transfer works, and what can be done afterwards is covered in why a second session is common.
Frequently asked questions
How common are lumps after fat transfer?
Irregularity is the commonest complication reported after facial fat transfer, and it is more likely in thin-skinned areas. Most lumps soften over the first months as the tissue settles. Some persist, and a persistent lump that is visible or palpable can be difficult to correct because the fat is your own tissue and there is no dissolving agent for it.
What is fat necrosis?
It is fat that has been transferred and has not established a blood supply, so the cells die. The dead fat is replaced by oil and scar tissue, which can form a small oil cyst or a firm area. Some resolve on their own, some are drained, and occasionally removal is needed. It is a recognised consequence of the operation rather than a technical error.
Are there serious risks beyond the cosmetic ones?
Infection, bleeding and the general risks of anaesthesia apply. Rare but serious complications include injury to structures near the injection site and embolic events, which is why placement technique and the depth and volume of each injection matter. Facial fat transfer is not a trivial procedure and should not be presented as one.
Risks & Limitations
- A proportion of the transferred fat is always reabsorbed. How much cannot be predicted, and a second session is common rather than exceptional.
- Irregularity, lumps or visible unevenness, which is more likely in thin-skinned areas such as the lower eyelid and tear trough.
- Fat necrosis and oil cysts where transferred fat fails to establish a blood supply; these may need aspiration or occasionally removal.
- Under-correction, the commonest reason for dissatisfaction, because less fat survived than was hoped.
- Bruising, swelling and soreness at the face and the donor site, with donor-site numbness and contour irregularity that can persist.
- Scars at the donor and recipient sites are permanent and mature over 6–12 months.
- Infection and bleeding; rare but serious risks include injury to structures near the injection site and embolic complications.
- General risks of anaesthesia, which a hospital setting manages but cannot remove.
When to Seek Care
- Difficulty breathing or shortness of breath — seek emergency care immediately.
- Rapidly increasing swelling, or a tense, painful, tight area.
- Fever above 38 °C, spreading redness, warmth, or discharge from an incision.
- A new lump that is painful, hot or growing, rather than one that is softening over months.
- Sudden change in vision after facial fat transfer.
References & Further Reading
- American Society of Plastic Surgeons (ASPS) — fat grafting and safety guidance
- International Society of Aesthetic Plastic Surgery (ISAPS)
- National Institute for Health and Care Excellence (NICE, UK) — relevant guidance
- Cochrane Library — systematic reviews in facial plastic surgery
This page is patient education, not medical advice, and it does not cite individual studies. Discuss your own case with a qualified clinician. To arrange an assessment at Chongqing West District Hospital, see Contact & Consultation.