Why does our mouth feel dry when we’re nervous?
When we feel nervous or anxious, our body triggers a physiological process called the “stress response.” This response is mainly controlled by the sympathetic nervous system, part of the autonomic nervous system, which causes several changes in the body, such as increased heart rate, elevated blood pressure, and faster breathing.
The physiology of saliva production:
- Parasympathetic nervous system: When we’re calm and relaxed, the parasympathetic nervous system is dominant. It stimulates the salivary glands to produce a lot of thin, watery saliva, which helps with digestion and keeping the mouth moist.
- Sympathetic nervous system: When the sympathetic nervous system is activated (in stress or anxiety), it causes the salivary glands to produce a smaller amount of thick, sticky saliva and inhibits the function of the parasympathetic system. This overall reduction in saliva is what leads to a dry mouth.
Why do we get a dry mouth when nervous?
- Sympathetic nervous system activation: During stress, the sympathetic nervous system is activated, reducing the function of the salivary glands.
- Redistribution of blood flow: To prepare for a “fight or flight” response, the body redirects blood away from non-essential functions, like digestion and salivation, to more critical areas like muscles and the heart, further reducing saliva production.
- Norepinephrine’s effect: The sympathetic nervous system releases norepinephrine, which causes the cells in the salivary glands to produce less saliva.
Examples:
- Before a public speech: Imagine someone about to give a speech in front of a large audience. They feel their heart racing, palms sweating, and suddenly their mouth feels dry. This happens because the nervousness activates their sympathetic nervous system, which decreases saliva production, causing the need to sip water frequently.
- Before an exam: A student feeling anxious before an exam may experience dry mouth, which can affect their focus. This is another example of how the body’s response to stress reduces saliva production.
- In an emergency: In situations like a car accident, people often feel nervous and experience dry mouth. The sympathetic nervous system activates to help the body respond to the emergency, but as a side effect, it decreases saliva flow.
Summary:
Dry mouth during stress or nervousness is a common physiological reaction caused by the activation of the sympathetic nervous system, which inhibits saliva production. This mechanism is part of the body’s natural way to prepare for potential threats, but understanding it helps us manage the discomfort, for example by using deep breathing techniques or drinking water to stay hydrated.