Why is only one side of my face sagging? Common reasons and signs not to wait on
You may have been startled while taking a photo, or in a lift mirror: “Hang on, only the left side has dropped.” I hear this quite often in consultations, so let me first separate the cases where you can relax from the cases where you should not.
The short answer
One-sided sagging that has come on slowly is, in most cases, a normal left-right difference that has grown with age. In a study that measured the faces of 191 people in 3D, asymmetry clearly increased with age (correlation coefficient 0.66), and it was greater in the lower two-thirds of the face. Sleeping side and differences in how fast bone and fat shrink add to this. However, if within a few days one corner of the mouth suddenly drops, an eye will not close properly or speech becomes slurred, this is not a cosmetic problem. It may be a sign of facial palsy or stroke, so go to an emergency department straight away. At Miso Clinic, 4F Bombom Building, 125 Dongdeok-ro, Jung-gu, Daegu (Exit 1, Kyungpook Nat'l Univ. Hospital Station), +82-53-428-2700, we measure left-right differences that have developed slowly and plan each side differently.
First, when should I go to hospital straight away?
- One side of the face sags suddenly, over hours to days
- One eye will not close properly, or water dribbles from the corner of the mouth when drinking
- Forehead lines will not form on one side
- Speech becomes slurred, or an arm or leg on one side goes weak
These can be facial nerve palsy or stroke. Call emergency services (119 in Korea) or go to the nearest emergency department first. Time matters especially when there are arm or leg symptoms or slurred speech. A cosmetic consultation comes after that.
Why does one-sided sagging develop slowly?
| Reason | What differs | Level of evidence |
|---|---|---|
| Left-right difference already there | Bone, muscle and fat differ slightly from the start | 191 people in 3D: asymmetry increased with age (r=0.66) |
| Sleeping side | Sleep wrinkles and stretched skin on the side that is always pressed | Sleep wrinkle review: differ from expression lines in cause and shape |
| Different rates of shrinkage | Bone and fat on one side shrink first, so hollowing comes first there | Same study: asymmetric bone change and fat loss suggested as causes |
| Chewing on one side | Difference in the size of the masseter muscle | Common in clinic, but I found no study measuring its link with sagging |
In my experience it is usually not one thing but two or three overlapping. That is why I always ask, “Which side do you sleep on?” and “Which side do you chew on?”
Is it sagging, or is it hollowing?
Sometimes one side looks lower but actually the other side has hollowed more. When the front of the cheek or the temple hollows first on one side, that side of the face looks longer and saggier. If you only pull up the side that seems saggy without telling these apart, the difference can actually grow.
Is the treatment the same on both sides?
No. If you put the same amount into a face whose sides differ, the difference stays as it was. So I measure each side separately and plan each side separately.
| Situation | How it is divided |
|---|---|
| The front of one cheek is more hollow | More dissolvable hyaluronic acid filler on that side |
| One masseter muscle is larger | A different botox dose on each side |
| The jawline and cheek on one side have come down more | A wider RF lifting area on that side |
| One corner of the mouth drops more | Mouth-corner botox focused on that side |
Perfect symmetry is not the goal. Human faces are not symmetrical to begin with. Reducing the difference that catches the eye is what looks natural.
What can I do at home?
- If you always lie on the same side, try gradually spending more time on your back
- If you chew only on one side, first check whether there is a dental problem (a sore tooth, your bite)
- Sun protection on both sides — many people get more sun on the driver’s side of the face
One-sided facial sagging: frequently asked questions
Is it normal for only one side of my face to sag?
If it came on slowly, it is in most cases a normal left-right difference that has grown with age. If it came on suddenly, go to an emergency department straight away.
Does my sleeping side make one side sag?
There is a review suggesting sleep wrinkles and stretched skin can form on the side that is always pressed. But few studies have measured the degree of sagging directly.
Will treatment make my face perfectly symmetrical?
Perfect symmetry is not the aim. We measure and plan each side separately to reduce the noticeable difference.
Where can I get a facial asymmetry or sagging consultation in Daegu?
At Miso Clinic, 4F Bombom Building, 125 Dongdeok-ro, Jung-gu, Daegu (Exit 1, Kyungpook Nat'l Univ. Hospital Station), +82-53-428-2700. Weekdays 11:00–19:00, Saturday 10:00–16:00, closed Sundays and public holidays.
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Related treatments: Lifting · Fine lines · Facial sagging consultation
Who wrote this
Written and reviewed by Lee Chi-Hak, MD, director of Miso Clinic, Daegu. The treatment standards and injection design set out here are the ones we use in practice.
| Medical director | Lee Chi-Hak, MD |
|---|---|
| Address | 4F Bombom Building, 125 Dongdeok-ro, Jung-gu, Daegu, South Korea · Exit 1, Kyungpook National University Hospital Station |
| Phone | +82-53-428-2700 |
| Hours | Weekdays 11:00–19:00 (lunch 13:00–14:00) / Saturday 10:00–16:00 (no lunch break) / Closed Sundays and public holidays |
| Columns | All clinical columns |
| Reference library | All booster and device references |
References
- Age and facial asymmetry — Linden OE et al. The Relationship between Age and Facial Asymmetry. Plast Reconstr Surg 2018;142(5):1145-52. PMID 30511968. 3D photographs of 191 people.
- Sleep wrinkles — Anson G, Kane MAC, Lambros V. Sleep Wrinkles: Facial Aging and Facial Distortion During Sleep. Aesthet Surg J 2016;36(8):931-40. PMID 27329660.
- Randomised sunscreen trial — Hughes MCB et al. Sunscreen and prevention of skin aging: a randomized trial. Ann Intern Med 2013;158(11):781-90. PMID 23732711. 903 people, 4.5 years.
- Korean medical advertising law — Korean Medical Service Act Article 56(2) (no treatment testimonials, no comparisons with other clinics, no superlatives). This is why this column carries no prices, reviews or before-and-after photos.
- Miso Clinic practice guidelines — for hollow cheeks, dissolvable hyaluronic acid filler is considered first; no RF treatment that day if there are metal or electronic implants, pregnancy or skin inflammation; botox is offered for all areas of the face.
Everything in this column is general information and does not replace medical diagnosis or treatment. Effects and side effects vary with individual skin condition, age and underlying illness, and the same result is not guaranteed for everyone. Any decision to proceed should be made in an in-person consultation with a physician.