Factors that can contribute to tongue thrusting include macroglossia (enlarged tongue), thumb sucking, large tonsils, hereditary factors, ankyloglossia (tongue tie), and certain types of artificial nipples used in feeding infants, also allergies or nasal congestion can cause the tongue to lie low in the mouth because of breathing obstruction and finally contributing to tongue thrusting. In addition, it is also seen after prolonged therapy by levodopa in Parkinsonism, also it occurs as extra pyramidal side effect (Acute muscular dystonia) after use of Neuroleptics (Anti-Psychotics).

Tongue thrust is normal in infants until approximately the age of six months. The loss of this normal infant behavior is one of the signs that the baby is ready to begin eating baby food.

Tongue thrusting can adversely affect the teeth and mouth. A person swallows from 1,200 to 2,000 times every 24 hours with about four pounds (1.8 kg) of pressure each time. If a person suffers from tongue thrusting, this continuous pressure tends to force the teeth out of alignment. Many people who tongue thrust have open bites; the force of the tongue against the teeth is an important factor in contributing to "bad bite" (malocclusion). Many orthodontists have completed dental treatment with what appeared to be good results, only to discover that the case relapsed because of the patient's tongue thrust. If the tongue is allowed to continue its pushing action against the teeth, it will continue to push the teeth forward and reverse the orthodontic work.

Speech is not frequently affected by the tongue thrust swallowing pattern. The "S" sound (lisping) is the one most affected. The lateral lisp (air forced on the side of the tongue rather than forward) shows dramatic improvement when the tongue thrust is corrected. However, lisping and tongue thrust are not always associated.

OMD refers to abnormal resting posture of the orofacial musculature, atypical chewing, and swallowing patterns, dental malocclusions, blocked nasal airways, and speech problems. OMD are patterns involving oral and/orofacial musculature that interferes with normal growth, development, or function of structures, or calls attention to itself. OMD are found in both children and adults. OMD that are commonly seen in children include tongue thrust that is also known as swallowing with an anterior tongue posture. OMD also refers to factors such as nonnutritive sucking behaviors, such as thumb sucking, clenching, bruxing, etc. that led to abnormal development of dentition and oral cavity. OMD in adult and geriatric population are due to various neurological impairments, oral hygiene, altered functioning of muscles due to aging, systemic diseases, etc.

Tongue thrusting is a type of orofacial myofunctional disorder, which is defined as habitual resting or thrusting the tongue forward and/or sideways against or between the teeth while swallowing, chewing, resting, or speaking. Abnormal swallowing patterns push the upper teeth forward and away from the upper alveolar processes and cause open bites. In children, tongue thrusting is common due to immature oral behavior, narrow dental arch, prolonged upper respiratory tract infections, spaces between the teeth (diastema), muscle weakness, malocclusion, abnormal sucking habits, and open mouth posture due to structural abnormalities of genetic origin. Large tonsils and adenoids also contribute to tongue thrust swallowing.

From the dental perspective, teeth move in relation to the balance of the soft tissue; the normal relationship of teeth lies in occlusion; and any deviation from the normal occlusion can lead to dental distress. Tongue posture plays an important role in swallowing and dentofacial growth. In case of tongue thrust swallowing, the tip of the tongue can come against or between the dentition; the midpoint may be collapsed or extended unilaterally or bilaterally; or the posterior part of the hard palate. In these conditions, there are chances of abnormal dentofacial growth and other concerns regarding development of the craniofacial complex.

There are pertinent symptomatic questions that can be considered for the diagnosis of tongue thrust swallow. Some of these questions are geared toward tongue protrusion and an opening of lips when the client is in repose; habitual mouth breathing; digit sucking; existence of high and narrow palatal arch; ankyloglossia (tongue-tie); malocclusions, (Class II, III); weak chewing muscles (masseter); weak lip muscles (orbicularis oris); overdeveloped chin muscles (mentalis); muscular imbalance; abnormal dentition.

Tongue thrusting and speech problems may co-occur. Due to unconventional postures of the tongue and other articulators, interdental and frontal lisping are very common. The alveolar sounds /s/ and /z/ are produced more anteriorly thus leading to interdental fricative like sounds, /th/.

Orofacial myofunctional disorders (OMD) (sometimes called “oral myofunctional disorder", and “tongue thrust”) are muscle disorders of the face, mouth, lips, or jaw.

Recent studies on incidence and prevalence of tongue thrust behaviors are not available. However, according to the previous research, 38% of various populations have OMD. The incidence is as high as 81% in children exhibiting speech/articulation problems (Kellum, 1992).

DES manifests as intermittent difficulty swallowing (dysphagia) for solid foods and liquids, and atypical chest pain. The chest pain may appear similar to cardiac chest pain (angina pectoris), so investigating the possible existence of heart disease is often indicated.

Signs of laryngeal paralysis include voice change (the dog's bark becomes hoarse-sounding), gagging or coughing (often during or after eating or drinking), exercise intolerance, inspiratory stridor (noisy breathing on inspiration), difficulty breathing, and in severe cases cyanosis or syncope (fainting). Secondary problems may also occur, including aspiration or edema in the lungs, though often the problem remains an upper respiratory problem. Affected dogs are vulnerable to heat stroke and heat exhaustion due to their limited ability to cool themselves down by panting, but the disorder itself can be mistaken for heat stroke.

Signs may occur at any time, but initially owners may only notice that their dog's bark sounds different, that their dog can't run as much as before, or that the dog has trouble in hot weather in unilateral cases because the unaffected side can compensate for the paralysed side. However most unilateral cases will eventually progress to include both sides of the larynx, a more serious problem with symptoms appearing more often.

Signs are usually worse in hot and humid weather, during exercise, during times of stress or excitement, and in obese pets. Acute or late-stage symptoms are usually unmistakable and require immediate emergency treatment.

Odynophagia (; from "-" "pain" and "" "to eat") is pain when swallowing. The pain may be felt in the mouth or throat and can occur with or without difficulty swallowing. The pain may be described as an ache, burning sensation, or occasionally a stabbing pain that radiates to the back. Odynophagia often results in inadvertent weight loss.

Diffuse esophageal spasm (DES) is a condition characterized by uncoordinated contractions of the esophagus, which may cause difficulty swallowing (dysphagia) or regurgitation. In some cases, it may cause symptoms such as chest pain, similar to heart disease. The cause of DES remains unknown.

Certain abnormalities on x-ray imaging are commonly observed in DES, such as a "corkscrew" or "rosary bead esophagus", although these findings are not unique to this condition. Specialized testing called manometry can be performed to evaluate the motor function of the esophagus, which can help identify abnormal patterns of muscle contraction within the esophagus that are suggestive of DES. The treatment of DES consists primarily of medications, such as acid suppressing agents (like proton pump inhibitors), calcium channel blockers, hyoscine butylbromide, or nitrates. In only extremely rare cases, surgery may be considered. People with DES have higher incidences of gastroesophageal reflux disease (GERD) and anxiety.

The "lump in the throat" sensation that characterizes globus pharyngis is often caused by inflammation of one or more parts of the throat, such as the larynx or hypopharynx, due to cricopharyngeal spasm, gastroesophageal reflux (GERD), laryngopharyngeal reflux or esophageal versatility.

In some cases the cause is unknown and symptoms may be attributed to a cause "i.e." a somatoform or anxiety disorder. It has been recognised as a symptom of depression, which responds to anti-depressive treatment.

Differential diagnosis must be made from Eagle syndrome which uses the patient's description of "something caught in my throat" as a diagnostic tool. Eagle syndrome is an elongation of the styloid process causing irritation to nerves and muscles in the region resulting in a number of unusual symptoms.

The results of recent studies have strongly suggested that GERD is a major cause of globus, though this remains under considerable debate.

A less common cause, distinguished by a "lump in the throat" accompanied with clicking sensation and considerable pain when swallowing, may be due to thyroid-cartilage rubbing against anomalous asymmetrical laryngeal anatomy "e.g." the superior cornu abrading against the thyroid lamina, surgically trimming the offending thyroid-cartilage provides immediate relief in all cases. However this cause is frequently misdiagnosed, despite requiring a simple clinical examination involving careful palpation of the neck side to side which elicits the same click sensation (laryngeal crepitus) and pain as when swallowing, most cases are due to prior trauma to the neck. High resolution computed tomographic (CT) or MRI scan of the larynx is usually required to fully understand the anomalous laryngeal anatomy. Anterior displacement of the thyroid ala on the affected side while swallowing can help resolve symptoms.

Laryngeal paralysis in animals is a condition in which the nerves and muscles that control the movements of one or both arytenoid cartilages of the larynx cease to function, and instead of opening during inspiration and closing during swallowing, the arytenoids remain stationary in a somewhat neutral position. Specifically, the muscle that causes abduction of the arytenoid cartilage, the cricoarytenoideus dorsalis muscle, ceases to function. This leads to inadequate ventilation during exercise and during thermoregulatory panting as well as incomplete protection of the airway during swallowing.

One of the commonest forms of laryngeal paralysis develops in geriatric medium to large breed dogs, in particular the Labrador retriever, but also some other breeds. This had been traditionally known as idiopathic largyngeal paralysis ("ILP": idiopathic means "of unknown cause"), and was believed to be a result of a condition affecting the nerves of the larynx (bilateral mononeuropathy of the recurrent laryngeal nerves). However investigations into ILP by two groups in Michigan and Tennessee between 2005 - 2013 showed that the condition was not limited to, or specifically a result of, dysfunction of the laryngeal nerves. Instead it was the most visible symptom of a slowly progressing polyneuropathy of old age, which also affected other nerves in the body. This finding, now generally believed correct following further research, has led to the proposed renaming of this type of laryngeal paralysis from "Idiopathic laryngeal paralysis" ("ILP") to "Geriatric onset laryngeal paralysis polyneuropathy" ("GOLPP").

Animals affected by laryngeal paralysis have reduced tolerance for exercise and heat and an increased risk of aspiration pneumonia. The condition is not generally regarded as causing pain, other than physical distress and anxiety caused by any difficulty in breathing or emotional distress from any difficulty with physical movement. Where laryngeal paralysis is related to a general progressive polyneuropathy, as in GOLPP, the nervous system will gradually degenerate causing increasing difficulty in management of the limbs (especially rear limbs), swallowing and breathing, and eventually in most cases euthanasia. Laryngeal paralysis is fairly common in large breed and geriatric dogs, particularly in the Labrador retriever, is rarely found in cats, and can also occur in horses where it is referred to as roaring, roarer's syndrome, or medically as laryngeal hemiplegia or recurrent laryngeal neuropathy (RLN). Laryngeal paralysis can be unilateral or bilateral depending upon dysfunction of one or both arytenoid cartilages.

Globus pharyngis (also known as globus sensation, globus or, somewhat outdatedly, globus hystericus, commonly referred to as having a "lump in one's throat"), is the persistent sensation of having phlegm, a pill or some other sort of obstruction in the throat when there is none. Swallowing can be performed normally, so it is not a true case of dysphagia, but it can become quite irritating. One may also feel mild chest pain or even severe pain with a clicking sensation when swallowing.

Odynophagia may have environmental or behavioral causes, such as:

- Very hot or cold food and drinks

- Taking certain medications

- Using drugs, tobacco, or alcohol

- Trauma or injury to the mouth, throat, or tongue

Megaesophagus, also known as esophageal dilatation, is a disorder of the esophagus in humans and other mammals, whereby the esophagus becomes abnormally enlarged. Megaesophagus may be caused by any disease which causes the muscles of the esophagus to fail to properly propel food and liquid from the mouth into the stomach (that is, a failure of peristalsis). Food can become lodged in the flaccid esophagus, where it may decay, be regurgitated, or may be inhaled into the lungs (leading to aspiration pneumonia).

Pseudodysphagia is the irrational fear of swallowing or choking. The symptoms are psychosomatic. The act of swallowing becomes mentally linked with choking or with undercapacity of the esophageal opening. This can induce panic reactions before or during the act of swallowing. The sensation of difficult swallowing feels authentic to the affected individual, although it is based on nothing in reality. It is important that dysphagia (difficult or painful swallowing) be ruled out before a diagnosis of pseudodysphagia is made.

Fear of choking is associated with anxiety, depression, panic attacks, hypochondriasis, and weight loss. The condition can occur in children and adults; it is equally common among males and females. Quality of life can be severely affected. Avoidance of restaurants or social settings is common, since sometimes food can only be taken in small bites or with liquid.

Characterization of idiopathic dysphagia as psychosomatic has recently been challenged by published case reports documenting instances of "pseudodysphagia" patients suffering from the little-known entity Omohyoid muscle syndrome. Should this syndrome be found to have a spectrum of severity (particularly if mild cases of OMS do not demonstrate the typical transient soft neck mass), the medical community may need to consider ruling out this subtle, truly somatic etiology before arriving at true pseudodysphagia, the latter being essentially a diagnosis of exclusion.

The main symptoms of achalasia are dysphagia (difficulty in swallowing), regurgitation of undigested food, chest pain behind the sternum, and weight loss. Dysphagia tends to become progressively worse over time and to involve both fluids and solids. Some people may also experience coughing when lying in a horizontal position.

The chest pain experienced, also known as cardiospasm and non-cardiac chest pain can often be mistaken for a heart attack. It can be extremely painful in some sufferers. Food and liquid, including saliva, are retained in the esophagus and may be inhaled into the lungs (aspiration).

Megaesophagus may occur secondary to diseases such as achalasia or Chagas disease. Achalasia is caused by a loss of ganglion cells in the myenteric plexus. There is a marked lack of contraction within the muscles involved in peristalsis with a constant contraction of the lower esophageal sphincter. Dilation of the esophagus results in difficulty swallowing. Retention of food bolus is also noted.

PVS sufferers often complain of a burning sensation with the tongue and oral mucosa, and atrophy of lingual papillae produces a smooth, shiny, red, dorsum of the tongue. Symptoms include:

Serial contrasted gastrointestinal radiography or upper gastrointestinal endoscopy may reveal the web in the esophagus. Blood tests show a hypochromic microcytic anemia that is consistent with an iron-deficiency anemia. Biopsy of involved mucosa typically reveals epithelial atrophy (shrinking) and varying amounts of submucosal chronic inflammation. Epithelial atypia or dysplasia may be present.It may also present as a post-cricoid malignancy which can be detected by loss of laryngeal crepitus. Laryngeal crepitus is found normally and is produced because the cricoid cartilage rubs against the vertebrae.

Achalasia (; "" + "-chalasia" "no relaxation") is a failure of smooth muscle fibers to relax, which can cause a sphincter to remain closed and fail to open when needed. Without a modifier, "achalasia" usually refers to achalasia of the esophagus, which is also called esophageal achalasia, achalasia cardiae, cardiospasm, and esophageal aperistalsis. Achalasia can happen at various points along the gastrointestinal tract; achalasia of the rectum, for instance, may occur in Hirschsprung's disease.

Esophageal achalasia is an esophageal motility disorder involving the smooth muscle layer of the esophagus and the lower esophageal sphincter (LES). It is characterized by incomplete LES relaxation, increased LES tone, and lack of peristalsis of the esophagus (inability of smooth muscle to move food down the esophagus) in the absence of other explanations like cancer or fibrosis.

Achalasia is characterized by difficulty in swallowing, regurgitation, and sometimes chest pain. Diagnosis is reached with esophageal manometry and barium swallow radiographic studies. Various treatments are available, although none cures the condition. Certain medications or Botox may be used in some cases, but more permanent relief is brought by esophageal dilatation and surgical cleaving of the muscle (Heller myotomy).

The most common form is primary achalasia, which has no known underlying cause. It is due to the failure of distal esophageal inhibitory neurons. However, a small proportion occurs secondary to other conditions, such as esophageal cancer or Chagas disease (an infectious disease common in South America). Achalasia affects about one person in 100,000 per year. There is no gender predominance for the occurrence of disease.

Dysphagia lusoria (or Bayford-Autenrieth dysphagia) is abnormal condition characterized by difficulty in swallowing caused by aberrant right subclavian artery. It was discovered by David Bayford in 1761 and first reported in a paper by the same in 1787.

Following clinical presentations may be used in the diagnosis of this condition.

1. Dizziness

2. Pallor of the conjuctiva and face

3. Erythematous oral mucosa with burning sensation

4. Breathelessness

5. Atropic and smooth tongue

6. Peripheral rhaggades around the oral cavity

The following tests are helpful in the diagnosis of Plummer–Vinson syndrome.

Symptoms of esophageal strictures include heartburn, bitter or acid taste in the mouth, choking, coughing, shortness of breath, frequent burping or hiccups, pain or trouble swallowing, throwing up blood, or weight loss.

Not all patients with Schatzki rings have symptoms; barium swallow tests of the esophagus sometimes show Schatzki rings in patients with no swallowing difficulties.

When Schatzki rings cause symptoms, they usually result in episodic difficulties with swallowing (dysphagia) solid foods, or a sensation that the food "sticks" while swallowing, especially if the food is not chewed thoroughly. Patients usually are able to regurgitate or force through the food material and resume eating. However, complete obstruction of the esophagus by a bolus of food (often called steakhouse syndrome) can occur. This can cause crushing chest pain and may need immediate treatment with endoscopy, which is the use of a specialized fibre-optic camera in order to remove the lodged food. After the obstruction is located, snares or forceps are inserted to pull the food out of the esophagus or to push it into the stomach. The latter is done with caution, usually when the anatomy of the structures around the obstruction is already known.

A Schatzki ring or Schatzki–Gary ring is a narrowing of the lower esophagus that can cause difficulty swallowing (dysphagia). The narrowing is caused by a ring of mucosal tissue (which lines the esophagus) or muscular tissue. A Schatzki ring is a specific type of "esophageal ring", and Schatzki rings are further subdivided into those above the esophagus/stomach junction (A rings), and those found at the squamocolumnar junction in the lower esophagus (B rings).

Patients with Schatzki rings can develop intermittent difficulty swallowing or, more seriously, a completely blocked esophagus. The ring is named after the German-American physician Richard Schatzki.

During development of aortic arch, if the proximal portion of the right fourth arch disappears instead of distal portion, the right subclavian artery will arise as the last branch of aortic arch. It then courses behind the esophagus (or rarely in front of esophagus, or even in front of trachea) to supply blood to right arm. This causes pressure on esophagus and results in dysphagia. It can sometimes result in upper gastrointestinal tract bleeding.

Phagophobia is a psychogenic dysphagia, a fear of swallowing. It is expressed in various swallowing complaints without any apparent physical reason detectable by physical inspection and laboratory analyses. An obsolete term for this condition is choking phobia, but it was suggested that the latter term is confusing and it is necessary to distinguish the fear of swallowing (i.e., of the propulsion of bolus) from fear of choking.

Phagophobia is classified as a specific phobia and according to DSM-IV classification it belongs to the category of "other phobias". Phagophobia may lead to (and be confused with) fear of eating, and the subsequent malnutrition and weight loss. In milder cases a phagophobe eats only soft and liquid foods.