When a Common Habit Could Signal Something More Serious
Drooling while you sleep is normal for many people—especially if you sleep on your side or stomach, breathe through your mouth, or are deeply relaxed.
But if you’ve recently started drooling excessively, notice it’s always on one side, or it’s accompanied by other unusual symptoms, it could be a sign of an underlying health issue—not just fatigue or pillow position.
The case of Xiao Liang—a young programmer whose one-sided drooling led to the early discovery of cerebral blood vessel blockage—is a powerful reminder: sometimes, the body’s quiet signals are urgent warnings.
Let’s explore when drooling is harmless—and when it’s worth a doctor’s visit.
🧠 First: Why Do We Drool During Sleep?
Saliva is produced by three major salivary glands (parotid, submandibular, sublingual) and hundreds of minor ones. It:
Keeps your mouth moist
Aids digestion
Fights bacteria
Helps with swallowing
During deep sleep, muscle tone relaxes, including in your face and throat. If you sleep with your mouth open (due to congestion, anatomy, or position), saliva can escape—no cause for concern.
✅ Normal drooling: Occasional, mild, bilateral (both sides), no other symptoms.
⚠️ Red flag drooling: Sudden, excessive, one-sided, or paired with weakness, numbness, or speech changes.
🔍 6 Medical Conditions Linked to Excessive or One-Sided Drooling
1. Neurological Disorders:
