Many different medical problems can cause swallowing difficulties. Patients with sudden damage to the nervous system, such as stroke, head injury or spinal cord injury, may have difficulty swallowing. Patients with diseases affecting muscle strength or coordination may have swallowing problems. For example, patients with various types of muscular dystrophy, cerebral palsy, or even diabetes may have difficulty swallowing. Patients who have progressive neurologic diseases such as Parkinson's disease, motor neuron disease (amyotrophic lateral sclerosis [ALS]), myasthenia gravis, multiple sclerosis [MS], or Alzheimer's disease may also have problems swallowing. Tumors of the head and neck and their treatment can cause swallowing problems, as can injuries to the neck or head. Other medical problems such as arthritis or scleroderma can cause swallowing difficulties, as can drying of the mouth (e.g., as a side effect of taking certain drugs).
These various medical problems cause swallowing difficulties because they either damage sensation or weaken or discoordinate one or more of the muscles involved in swallowing. As a result, food enters the lungs or stays in the mouth or pharynx after the swallow. In this latter case, repeated swallows and increased effort are required.
Though each of these diseases or types of damage may cause different types of swallowing problems, the patients have one thing in common. They have difficulty eating safely and efficiently.