The tube has a light and camera on the end of it. This allows the doctor to see the inside of the throat and airways. This test is useful to detect conditions such as vocal cord paralysis, or a tumor or cancer in the throat or lungs. Long-term effects are related to the cause. For example, cases due to infection often go away and have no long-term effects.
Cancer can result in death.
Cases due to nervous system conditions may sometimes be permanent. Noisy breathing itself is not contagious. If the cause is an infection, such as pneumonia, the infection may be transmitted to others. Treatment is directed at the cause. A person with an infection may need antibiotics.