Diseases of the lung can be analyzed with bronchoscopy by sampling the lung tissue through the use of a bronchoscope. Samples are sent to a laboratory for analysis, from which a physician can make a diagnosis.

Patient Information
The pulmonologist (a lung specialist trained to perform a bronchoscopy) sprays a topical or local anesthetic in the mouth and throat. This will cause coughing at first, which will stop as the anesthetic begins to work. When the area feels "thick," it is sufficiently numb. Medications may be given through an IV to help the patient relax.
If the bronchoscopy is performed via the nose, an anesthetic jelly will be inserted into one nostril. The scope will be inserted through the numbed nostril until it passes through the throat into the trachea and bronchi.
A flexible bronchoscope is used. The flexible tube is less than 1/2-inch wide and about 2 feet long. As the bronchoscope is used to examine the airways of the lungs, the physician doctor will obtain samples of lung secretions to send for laboratory analysis.
Saline solution is introduced to flush the area and collect cells to be analyzed by a pathologist or microbiologist. This part of the procedure is called a "lavage" or a bronchial washing. Usually, small amounts (5-10 cc, or 1-2 teaspoons) of saline are used.
In certain circumstances, a larger volume of saline may be used. In this procedure, called bronchoalveolar lavage, up to 300 cc of saline (20 tablespoons) are instilled into the airway after the bronchoscope has been advanced as far as possible and a small airway is temporarily blocked by the scope. Bronchoalveolar lavage is performed to obtain a sample of the cells, fluids, and other materials present in the very small alveoli (air sacs).
In addition, tiny brushes, needles, or forceps may be introduced through the bronchoscope to obtain tissue samples from the lungs. Occasionally, stenting and laser therapies can be performed through the bronchoscope. A rigid bronchoscope is less commonly used, and usually requires general anesthesia.

Before the Procedure
The night before your bronchoscopy, DO NOT eat or drink anything (not even water) after midnight. It is important that your stomach be empty.  Your physician should tell you if you should take your medications with a sip of water on the morning of the procedure. 

After the Procedure
When the procedure is finished, you will be observed by a nurse. It is normal to cough up a small amount of blood for 1-2 days after the procedure. The nurse will recheck your blood pressure, pulse and respiratory rate prior to your discharge. The IV needle will be removed, and a radiograph of the chest may be taken. You cannot eat or drink anything for 2 hours after the procedure.  When you are ready to be discharged, the nurse will go over some instructions with you, such as what to do for a sore throat.