A swallow test is a medical procedure used to evaluate the function of the swallowing mechanism, a complex process medically known as deglutition. This assessment is performed when a person experiences difficulty swallowing, a condition called dysphagia. The goal of the test is to pinpoint the exact nature and location of the problem within the throat (pharynx) and the food pipe (esophagus). By observing the movement of food and liquid through the upper digestive tract, clinicians determine if the airway is being protected during swallowing. This diagnostic step helps manage a person’s diet safely and prevent serious health complications.
Why is the Test Ordered?
A doctor recommends a swallow test when specific indications suggest that the swallowing process is compromised. One common symptom is the sensation of food or liquid getting stuck in the throat or chest. Persistent, unexplained weight loss may also prompt a referral, as difficulty swallowing can significantly reduce a person’s nutritional intake.
Recurrent pneumonia, often referred to as aspiration pneumonia, is a serious concern that necessitates this testing. This lung infection occurs when food, liquid, or saliva accidentally enters the airway instead of the esophagus, a process called aspiration.
The need for a swallow test is also associated with underlying neurological conditions that impair muscle control, including stroke, Parkinson’s disease, multiple sclerosis, and dementia. Patients who have undergone treatment for head and neck cancer are routinely evaluated due to potential structural changes that affect swallowing.
Understanding the Main Diagnostic Types
Two main instrumental procedures are used to provide a detailed, objective analysis of the swallowing process: the Modified Barium Swallow Study and the Fiberoptic Endoscopic Evaluation of Swallowing. These tests are not interchangeable, and the choice depends on the specific clinical questions being asked. Both allow a Speech-Language Pathologist (SLP) to observe the function of the muscles and structures involved in swallowing in real-time.
Modified Barium Swallow Study (MBSS)
The MBSS, also known as a Videofluoroscopic Swallow Study (VFSS), uses a real-time X-ray technique called fluoroscopy. The patient swallows various consistencies of food and liquid coated with barium, a contrast material that appears white on the X-ray screen. This allows the clinician to view the entire swallowing mechanism, from the mouth, through the throat, and into the esophagus. Because it uses X-rays, the test is performed in a radiology suite and is time-limited to minimize radiation exposure.
Fiberoptic Endoscopic Evaluation of Swallowing (FEES)
FEES uses a thin, flexible endoscope equipped with a camera. The clinician passes this tube through the patient’s nose to position the camera just above the voice box (larynx) and throat structures. The patient is given food and liquids, often mixed with a colored dye for better visibility, and the SLP observes the process on a monitor. FEES provides a clear, color view of the anatomy, but the camera view is temporarily obscured during the actual swallow. Unlike the MBSS, FEES is portable and can be performed at a patient’s bedside without radiation exposure concerns.
Preparing for and Experiencing the Test
Preparation for a swallow test is minimal, but patients are often asked to avoid eating or drinking for a few hours beforehand. If the MBSS is being performed, patients must remove any jewelry or clothing with metal near the neck area. Patients who wear dentures or use specific eating utensils are advised to bring them to the test to simulate a typical mealtime experience.
During the procedure, the patient is seated upright in a chair or on an X-ray table. A specialized clinician, usually a Speech-Language Pathologist, guides the patient through the process. The patient is asked to swallow small amounts of different food and liquid consistencies, including:
- Thin liquids
- Nectar-thick and honey-thick liquids
- Pureed foods like applesauce
- Solid foods like crackers
The clinician may ask the patient to try specific head positions or swallowing maneuvers to see if they improve swallowing safety. The entire examination is quick, often lasting only 15 to 30 minutes. After a barium study, patients are encouraged to drink plenty of fluids to help the contrast material pass through their system and prevent temporary constipation.
What the Results Determine
The results of a swallow test translate directly into a personalized plan for safe eating and drinking. The primary diagnostic outcome is confirming the presence and specific characteristics of dysphagia. Clinicians identify the exact stage of the swallow that is impaired and the physiological cause, such as poor tongue control or weak pharyngeal muscle contraction.
A significant finding is the identification of aspiration, which is when material enters the airway below the vocal cords, or penetration, where material enters the airway entrance but remains above the vocal cords. Based on these findings, the clinician recommends modifications to the patient’s diet, often involving specific food textures and liquid consistencies that can be swallowed safely. The results also guide a therapeutic plan involving specific swallowing exercises and maneuvers designed to strengthen weak muscles, improve the timing of the swallow reflex, and teach compensatory strategies to minimize the risk of food entering the lungs.