Esophageal obstruction is caused by benign or malignant lesions within the lumen, wall or outside the wall of the esophagus. These lesions block the passage of food leading to dysphagia with consequent nutritional deficiencies. The diagnosis of the condition depends on history, clinical examination, esophagoscopy, and radiological investigations.
Esophageal obstruction can be complete or partial and is caused by benign or malignant tumors or foreign bodies located within the lumen, wall (intramural) or outside the wall (extrinsic obstruction) of the esophagus. Intraluminal causes besides the above-mentioned etiologies include strictures secondary to corrosive ingestion, esophagitis (secondary to gastroesophageal reflux or infections) and esophageal webs which can be congenital or acquired. Intramural tumors can cause obstruction by narrowing the esophagus. Similarly, extrinsic factors like thyromegaly, cervical swellings, anomalous blood vessels (dysphagia lusoria), aneurysms of the aorta, left atrial enlargement, vertebral osteophytes, and malignant pulmonary tumors can compress the esophagus leading to obstruction of its lumen.
Patients present with progressively increasing dysphagia to either solids or liquids depending upon the etiology of the obstruction. In malignant lesions, the dysphagia to solids is the initial symptom, progressing to semi-solids and finally to liquids . Anorexia, loss of appetite, weight loss, asthenia and nutritional deficiencies develop over a period of time. Drooling may be noticed if there is a complete luminal obstruction. This leads eventually to cachexia and influences the patient's quality and duration of life  . The nutritional status in these patients determines the prognosis . Patients with partial esophageal obstruction may have a sensation of food or foreign body getting stuck in the throat.
The workup in a case of this disease includes history taking, complete physical and neurological examination, followed by laboratory tests, endoscopic evaluation, and imaging studies. Anamnestic data will provide information on the foreign body or caustic ingestion and details about the onset, duration, progress and degree of dysphagia. Physical examination will help detect nutritional abnormalities, thyromegaly, and cardiac or pulmonary etiology of the swallowing dysfunction. A thorough neurological examination is required to exclude neuromuscular causes of dysphagia.
Laboratory tests such as vitamin B12 levels, thyroid stimulating hormone levels (TSH) and creatine kinase should be ordered as part of the workup.
A plain X-ray chest may reveal a lung tumor or an enlarged left atrium compressing the esophagus. Non-invasive imaging studies like videofluoroscopy  and barium swallow help to diagnose mucosal and obstructive lesions while computed tomography and magnetic resonance imaging are required to delineate the extent of the obstructive growths and can also detect anomalous blood vessels.
Esophagoscopy is the gold standard test to detect the cause of the esophageal obstruction , to remove a foreign body, dilate a stricture or obtain tissue for histological evaluation.
If gastroesophageal reflux is suspected, then 24 hour pH monitoring will be required to diagnose the cause. Electromyography  and manometry can also be performed if indicated by history and physical examination findings.