How to Determine Which Side of the Face Is Affected by Facial Paralysis
Facial paralysis can be confusing, especially for patients who may not immediately recognize which side of their face is affected. Often, individuals mistakenly assume the side they feel discomfort on is the affected one—when in reality, it might still be functioning normally. To accurately identify the impaired side, several simple but effective physical tests can be performed at home or with a healthcare provider.
Key Physical Tests to Identify Facial Weakness
1. Puffing the Cheeks (Puff Test)
One of the most reliable ways to detect facial paralysis is the "puff test." Ask the person to puff out both cheeks and hold the air in their mouth. Observe carefully: if one side collapses or fails to inflate properly, that side is likely affected. In healthy individuals, both sides of the face will bulge evenly. Asymmetry during this test strongly suggests nerve dysfunction on the weaker side.
2. Smiling or Baring Teeth
Instruct the individual to smile broadly or show their teeth. Pay close attention to the corners of the mouth. If one corner droops or doesn't lift as high as the other, that side is likely paralyzed. Normally, both sides of the mouth should rise symmetrically when smiling. A noticeable downward pull on one side indicates weakened facial muscles due to nerve impairment.
3. Eye Closure Test
Another critical indicator is the ability to close the eyes completely. Have the person gently shut their eyes. If one eye remains slightly open or feels like it can't fully close, that side is typically affected by facial paralysis. This is known as "incomplete palpebral closure" and is common in conditions like Bell's palsy. Some patients may also notice increased tearing or dryness on the affected side due to improper eyelid function.
4. Forehead Movement and Wrinkling
Ask the patient to raise their eyebrows or look upward while wrinkling their forehead. Compare the depth and presence of forehead lines (wrinkles) on both sides. A reduction or absence of wrinkles on one side points to upper facial muscle weakness, which is a hallmark sign of peripheral facial nerve damage. If the person cannot lift one eyebrow or has significantly less movement, that side is likely impacted.
Additional Clues: Ear Pain and Early Symptoms
In cases where facial paralysis is caused by inflammation of the facial nerve—such as in Bell's palsy—patients often experience pain behind the ear on the same side as the paralysis. This retro-auricular pain usually appears in the early stages, sometimes even before visible facial drooping occurs. Noticing this symptom early can help with quicker diagnosis and treatment initiation.
It's important to remember that sudden onset of facial weakness should always be evaluated by a medical professional to rule out serious causes like stroke, infection, or tumors. However, using these self-assessment techniques can provide valuable clues and help communicate symptoms more clearly during a clinical evaluation.
When to Seek Medical Help
If any signs of facial asymmetry, difficulty making expressions, or unexplained ear pain occur suddenly, prompt medical consultation is essential. Early intervention—especially within 72 hours—can significantly improve recovery outcomes, particularly when corticosteroids or antiviral medications are appropriate. Never ignore sudden changes in facial movement; timely action supports better long-term results.