What does this mean?
One side of the face dropping means that the facial nerve driving the muscles of expression on that side, or the part of the brain controlling that nerve, has been affected. Not being able to raise your eyebrow, not being able to close your eyelid fully, one corner of your mouth sagging and water leaking from the corner of your lip when you drink are different faces of the same problem. This picture is not explained by toothache or by the jaw joint.
The forehead is what gets looked at. Where the nerve is affected after it has reached the face, the forehead is involved too: the eyebrow cannot be raised and the forehead cannot be wrinkled. Where the cause lies in the brain, the forehead is usually spared and the drooping shows mainly around the mouth. Making this distinction at home is not something you should attempt: the rule has a margin of error, and the decision rests on examination and scans.
With this sign, time is what decides. The window for stroke treatment is measured in hours. And in the conditions that remain once a cause in the brain has been ruled out, starting medication within the first few days affects the outcome. Waiting to see whether it passes is not a real option for this symptom.
The causes of a drooping face range from those needing action within the hour to those expected to improve with time; the order below is not set by likelihood, but by what has to be ruled out first.
Likely causes
What helps at home?
- If your eyelid does not close fully, protect your eye; the clear front surface of an eye that stays open dries out and is damaged quickly, and your doctor decides how it should be protected.
- If you notice your speech slurring or weakness in your arm or leg, call 112 without waiting.
- Do not push your facial muscles through exercises, and do not try massage or heat on your own; whether and when these have a place is decided after the assessment.
- Slow down when you eat and drink; food can collect inside the drooping cheek and drink can escape from the corner of your lip.
- If the drooping came on suddenly it needs assessment in an emergency department, not waiting at home
- If there is slurred speech, weakness in an arm or leg, or loss of balance, call 112 without losing time
- If it comes with blurred vision, double vision or a headache unusually severe for you
- If there is earache, or blisters or a rash on the outer ear or inside the mouth
- If your eyelid does not close at all; protecting the eye has to be planned the same day
Frequently asked questions
- Is this a stroke or a facial palsy?
- It is not possible to settle this from a description of the symptom, and trying to is not the right approach either. Both can drop one side of the face, but how urgent they are and how they are treated are completely different. The right order is this: a cause in the brain is ruled out first in an emergency department, and the assessment then carries on for what remains.
- My face dropped after dental treatment; could it be related to the procedure?
- After an anaesthetic given in the lower jaw, the drug can reach the facial nerve and cause temporary drooping; this usually settles within hours, along with the anaesthetic itself. Drooping that has not resolved by the end of the same day, or that starts days after the procedure, cannot be explained this way and has to be assessed separately. In both cases the dentist who carried out the procedure needs to be told.
- Will this get better?
- It depends on the cause and cannot be said at the outset. In some cases function comes back markedly over weeks to months; in others, some trace can remain. High among the things that shape the outcome is how long the assessment was put off, which is why you should be seen the same day rather than wait and see.
This content is for general information and does not replace an in-person examination. Symptoms overlap between conditions, and a diagnosis can only be made clinically.