The most common symptoms of GERD in adults are an acidic taste in the mouth, regurgitation, and heartburn. Less common symptoms include pain with swallowing/sore throat, increased salivation (also known as water brash), nausea, chest pain, and coughing.

GERD sometimes causes injury of the esophagus. These injuries may include one or more of the following:

- Reflux esophagitis – inflammation of esophageal epithelium which can cause ulcers near the junction of the stomach and esophagus

- Esophageal strictures – the persistent narrowing of the esophagus caused by reflux-induced inflammation

- Barrett's esophagus – intestinal metaplasia (changes of the epithelial cells from squamous to intestinal columnar epithelium) of the distal esophagus

- Esophageal adenocarcinoma – a form of cancer

Some researchers have proposed that recurrent ear infections, and idiopathic pulmonary fibrosis might be tied, in some cases, to GERD; however, a causative role has not been established. GERD does not appear to be linked to chronic sinusitis.

Most damage to the pyloric valve occurs as a complication of gastric surgery. Other causes of biliary reflux may be:

- Peptic ulcer

- Gallbladder surgery (cholecystectomy)

A significant fraction of cases are idiopathic, with no identified specific etiology.

GERD may be difficult to detect in infants and children, since they cannot describe what they are feeling and indicators must be observed. Symptoms may vary from typical adult symptoms. GERD in children may cause repeated vomiting, effortless spitting up, coughing, and other respiratory problems, such as wheezing. Inconsolable crying, refusing food, crying for food and then pulling off the bottle or breast only to cry for it again, failure to gain adequate weight, bad breath, and burping are also common. Children may have one symptom or many; no single symptom is universal in all children with GERD.

Of the estimated 4 million babies born in the US each year, up to 35% of them may have difficulties with reflux in the first few months of their lives, known as 'spitting up'. One theory for this is the "fourth trimester theory" which notes most animals are born with significant mobility, but humans are relatively helpless at birth, and suggests there may have once been a fourth trimester, but children began to be born earlier, evolutionarily, to accommodate the development of larger heads and brains and allow them to pass through the birth canal and this leaves them with partially undeveloped digestive systems.

Most children will outgrow their reflux by their first birthday. However, a small but significant number of them will not outgrow the condition. This is particularly true when a family history of GERD is present.

Biliary reflux, bile reflux or duodenogastric reflux is a condition that occurs when bile flows upward (refluxes) from the duodenum into the stomach and esophagus.

Biliary reflux can be confused with acid reflux, also known as gastroesophageal reflux disease (GERD). While bile reflux involves fluid from the small intestine flowing into the stomach and esophagus, acid reflux is backflow of stomach acid into the esophagus. These conditions are often related, and differentiating between the two can be difficult.

Bile is a digestive fluid made by the liver, stored in the gallbladder, and discharged into duodenum after food is ingested to aid in the digestion of fat. Normally, the pyloric sphincter prevents bile from entering the stomach. When the pyloric sphincter is damaged or fails to work correctly, bile can enter the stomach and then be transported into the esophagus as in gastric reflux. The presence of small amounts of bile in the stomach is relatively common and usually asymptomatic, but excessive refluxed bile causes irritation and inflammation.

Nutcracker esophagus is characterized as a motility disorder of the esophagus, meaning that it is caused by abnormal movement, or peristalsis of the esophagus. Patients with motility disorders present with two key symptoms: either with chest pain (typically reported as non-cardiac chest pain as it is esophageal in origin), which is usually found in disorders of spasm, or with dysphagia (difficulty with swallowing). Nutcracker esophagus can present with either of these, but chest pain is the more common presentation. The chest pain is very severe and intense, and mimics cardiac chest pain. It may spread into the arm and back. The symptoms of nutcracker esophagus are intermittent, and may occur with or without food. Rarely, patients can present with a sudden obstruction of the esophagus after eating food (termed a food bolus obstruction, or the 'steakhouse syndrome') requiring urgent treatment. The disorder does not progress to produce worsening symptoms or complications, unlike other motility disorders (such as achalasia) or anatomical abnormalities of the esophagus (such as peptic strictures or esophageal cancer). Many patients with nutcracker esophagus do not have any symptoms at all, as esophageal manometry studies done on patients without symptoms may show the same motility findings as nutcracker esophagus. Nutcracker esophagus may also be associated with metabolic syndrome. The incidence of nutcracker esophagus in all patients is uncertain.

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.

Esophageal stricture, or narrowing of the esophagus, is usually a complication of acid reflux, most commonly due to gastroesophageal reflux (GERD). These patients are usually older and have had GERD for a long time. Esophageal stricture can also be due to other causes, such as acid reflux from Zollinger-Ellison syndrome, trauma from a nasogastric tube placement, and chronic acid exposure in patients with poor esophageal motility from scleroderma. Other non-acid related causes of peptic strictures include infectious esophagitis, ingestion of chemical irritant, pill irritation, and radiation. Peptic stricture is a progressive mechanical dysphagia, meaning patients will complain of initial intolerance to solids followed by inability to tolerate liquids. When the diameter of the stricture is less than 12 mm the patient will always have dysphagia, while dysphagia is not seen when the diameter of the stricture is above 30 mm. Symptoms relating to the underlying cause of the stricture usually will also be present.

Esophageal cancer also presents with progressive mechanical dysphagia. Patients usually come with

rapidly progressive dysphagia first with solids then with liquids, weight loss (> 10 kg), and anorexia (loss of appetite). Esophageal cancer usually affects the elderly. Esophageal cancers can be either squamous cell carcinoma or adenocarcinoma. Adenocarcinoma is the most prevalent in the US and is associated with patients with chronic GERD who have developed Barrett's esophagus (intestinal metaplasia of esophageal mucosa). Squamous cell carcinoma is more prevalent in Asia and is associated with tobacco smoking and alcohol use.

Esophageal rings and webs, are actual rings and webs of tissue that may occlude the esophageal lumen.

- "Rings" --- Also known as Schatzki rings from the discoverer, these rings are usually mucosal rings rather than muscular rings, and are located near the gastroesophageal junction at the squamo-columnar junction. Presence of multiple rings may suggest eosinophilic esophagitis. Rings cause intermittent mechanical dysphagia, meaning patients will usually present with transient discomfort and regurgitation while swallowing solids and then liquids, depending on the constriction of the ring.

- "Webs" --- Usually squamous mucosal protrusion into the esophageal lumen, especially anterior cervical esophagus behind the cricoid area. Patients are usually asymptomatic or have intermittent dysphagia. An important association of esophageal webs is to the Plummer-Vinson syndrome in iron deficiency, in which case patients will also have anemia, koilonychia, fatigue, and other symptoms of anemia.

Achalasia is an idiopathic motility disorder characterized by failure of lower esophageal sphincter (LES) relaxation as well as loss of peristalsis in the distal esophagus, which is mostly smooth muscle. Both of these features impair the ability of the esophagus to empty contents into the stomach. Patients usually complain of dysphagia to both solids and liquids. Dysphagia to liquids, in particular, is a characteristic of achalasia. Other symptoms of achalasia include regurgitation, night coughing, chest pain, weight loss, and heartburn. The combination of achalasia, adrenal insufficiency, and alacrima (lack of tear production) in children is known as the triple A (Allgrove) syndrome. In most cases the cause is unknown (idiopathic), but in some regions of the world, achalasia can also be caused by Chagas disease due to infection by "Trypanosoma cruzi".

Scleroderma is a disease characterized by atrophy and sclerosis of the gut wall, most commonly of the distal esophagus (~90%). Consequently, the lower esophageal sphincter cannot close and this can lead to severe gastroesophageal reflux disease (GERD). Patients typically present with progressive dysphagia to both solids and liquids secondary to motility problems or peptic stricture from acid reflux.

Spastic motility disorders include diffuse esophageal spasm (DES), nutcracker esophagus, hypertensive lower esophageal sphincter, and nonspecific spastic esophageal motility disorders (NEMD).

- "DES" can be caused by many factors that affect muscular or neural functions, including acid reflux, stress, hot or cold food, or carbonated drinks. Patients present with intermittent dysphagia, chest pain, or heartburn.

Rare causes of esophageal dysphagia not mentioned above

- Diverticulum

- Aberrant subclavian artery, or (dysphagia lusoria)

- Cervical osteophytes

- Enlarged aorta

- Enlarged left atrium

- Mediastinal tumor

If there is dysphagia to both solids and liquids, then it is most likely a motility problem. If there is dysphagia initially to solids but progresses to also involve liquids, then it is most likely a mechanical obstruction. Once a distinction has been made between a motility problem and a mechanical obstruction, it is important to note whether the dysphagia is intermittent or progressive. An intermittent motility dysphagia likely can be diffuse esophageal spasm (DES) or nonspecific esophageal motility disorder (NEMD). Progressive motility dysphagia disorders include scleroderma or achalasia with chronic heartburn, regurgitation, respiratory problems, or weight loss. Intermittent mechanical dysphagia is likely to be an esophageal ring. Progressive mechanical dysphagia is most likely due to peptic stricture or esophageal cancer.

It can be caused by or associated with gastroesophageal reflux disease, esophagitis, a dysfunctional lower esophageal sphincter, disordered motility, lye ingestion, or a hiatal hernia. Strictures can form after esophageal surgery and other treatments such as laser therapy or photodynamic therapy. While the area heals, a scar forms, causing the tissue to pull and tighten, leading to difficulty in swallowing.

The signs and symptoms for esophagitis include:

- Heartburn feels like the inside of your chest is burning. It is a symptom of acid reflux or GERD.

- Nausea is the feeling of being sick, specifically with the urge to vomit.

- Swallowing is painful and difficult to pass food through your throat into your esophagus.

- Vomiting, also known as emesis, is the release of the contents of the stomach through the mouth or nose.

- Abdominal pain is when pain is felt in the abdomen.

- Food bolus impaction is an obstruction of the esophagus by swallowed food.

- Acid regurgitation is the backflow of acid from the stomach to the mouth.

- Chest pain is pain felt between the neck and upper abdomen. There are many causes and the pain can range.

- Cough is a reflex to clear the throat of irritants or mucus.

A doctor should be consulted if the signs and/or symptoms do not subside after a few days, are accompanied with flu-like symptoms, do not lessen after treating with over-the counter antacids, and/or make eating food difficult.

The change from normal to premalignant cells that indicate Barrett's esophagus does not cause any particular symptoms. Barrett's esophagus, however, is associated with these symptoms:

- frequent and longstanding heartburn

- trouble swallowing (dysphagia)

- vomiting blood (hematemesis)

- pain under the sternum where the esophagus meets the stomach

- unintentional weight loss because eating is painful (odynophagia)

The risk of developing Barrett's esophagus is increased by central obesity (vs. peripheral obesity). The exact mechanism is unclear. The difference in distribution of fat among men (more central) and women (more peripheral) may explain the increased risk in males.

Extraesophageal symptoms result from exposure of the upper aerodigestive tract to gastric contents. This causes a variety of symptoms, including hoarseness, postnasal drip, sore throat, difficulty swallowing, indigestion, chronic cough, wheezing, globus pharyngeus, and chronic throat-clearing. Some people with LPR have heartburn, while others have little to no heartburn as refluxed stomach contents do not remain in the esophagus long enough to irritate the surrounding tissue. Individuals with more severe forms of LPR may experience abrasion of tooth enamel due to intermittent presence of gastric contents in the oral cavity.

Additionally, LPR can cause inflammation in the vocal tract which results in the symptom of dysphonia or hoarseness. Hoarseness is considered to be one of the primary symptoms of LPR and is associated with complaints such as strain, vocal fatigue, muskuloskeletal tension, and hard glottal attacks, all of which can reduce a person's ability to communicate effectively. Moreover, LPR patients may try to compensate for their hoarseness by increasing muscular tension in their vocal tract. This hyper-functional technique adopted in response to the inflammation caused by LPR can lead to a condition called muscle tension dysphonia and may persist even after the hoarseness and inflammation has disappeared. A speech-language pathologist will often need to be involved to help resolve this maladaptive, compensatory pattern through the implementation of voice therapy.

LPR presents as a chronic and intermittent disease in children. LPR in children and infants tends to manifest with a unique set of symptoms. Symptoms seen in children with LPR include a cough, hoarseness, stridor, sore throat, asthma, vomiting, globus sensation, wheezing, aspiration and recurrent pneumonia. Common symptoms of LPR in infants include wheezing, stridor, persistent or recurrent cough, apnea, feeding difficulties, aspiration, regurgitation, and failure to thrive. Moreover, LPR in children is commonly concomitant with laryngeal disorders such as laryngomalacia, subglottic stenosis, and laryngeal papillomatosis.

Nutcracker esophagus, or hypertensive peristalsis, is a disorder of the movement of the esophagus characterized by contractions in the smooth muscle of the esophagus in a normal sequence but at an excessive amplitude or duration. Nutcracker esophagus is one of several motility disorders of the esophagus, including achalasia and diffuse esophageal spasm. It causes difficulty swallowing, or dysphagia, to both solid and liquid foods, and can cause significant chest pain; it may also be asymptomatic. Nutcracker esophagus can affect people of any age, but is more common in the sixth and seventh decades of life. The diagnosis is made by an esophageal motility study (esophageal manometry), which evaluates the pressure of the esophagus at various points along its length. The term "nutcracker esophagus" comes from the finding of increased pressures during peristalsis, with a diagnosis made when pressures exceed 180 mmHg; this has been likened to the pressure of a mechanical nutcracker. The disorder does not progress, and is not associated with any complications; as a result, treatment of nutcracker esophagus targets control of symptoms only.

Barrett's esophagus refers to an abnormal change (metaplasia) in the cells of the lower portion of the esophagus. It is characterized by the replacement of the normal stratified squamous epithelium lining of the esophagus by simple columnar epithelium with goblet cells (which are usually found lower in the gastrointestinal tract). The medical significance of Barrett's esophagus is its strong association (0.1 per 1 cm Prague C>M> total segment length per patient-year) with esophageal adenocarcinoma, a very often deadly cancer, because of which it is considered to be a premalignant condition.

The main cause of Barrett's esophagus is thought to be an adaptation to chronic acid exposure from reflux esophagitis. The incidence of esophageal adenocarcinoma has increased substantially in the Western world in recent years. The condition is found in 5–15% of patients who seek medical care for heartburn (gastroesophageal reflux disease), although a large subgroup of patients with Barrett's esophagus do not have symptoms. Diagnosis requires endoscopy (more specifically, esophagogastroduodenoscopy, a procedure in which a fibreoptic cable is inserted through the mouth to examine the esophagus, stomach, and duodenum) and biopsy. The cells of Barrett's esophagus, after biopsy, are classified into four general categories: nondysplastic, low-grade dysplasia, high-grade dysplasia, and frank carcinoma. High-grade dysplasia and early stages of adenocarcinoma can be treated by endoscopic resection and new endoscopic therapies such as radiofrequency ablation, whereas advanced stages (submucosal) are generally advised to undergo surgical treatment. Nondysplastic and low-grade patients are generally advised to undergo annual observation with endoscopy, with radiofrequency ablation as a therapeutic option. In high-grade dysplasia, the risk of developing cancer might be at 10% per patient-year or greater.

The condition is named after the Australian-born British thoracic surgeon Norman Barrett (1903–1979), who described it in 1950.

Those with the eating disorder bulimia are more likely to develop Barrett’s esophagus because bulimia can cause severe acid reflux, and because purging also floods the esophagus with acid.

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).

The severity of reflux esophagitis is commonly classified into four grades according to the "Los Angeles Classification":

Esophageal spasm is rare. Often, symptoms that may suggest esophageal spasm are the result of another condition such as gastroesophageal reflux disease (GERD) or achalasia. The symptoms can also include dysphagia, regurgitation, noncardiac chest pain, heartburn, globus pharyngis (which is a feeling that something is stuck in the throat) or a dry cough.

LPR is often regarded as a subtype of GERD that occurs when stomach contents flow upward through the esophagus and reach the level of the larynx and pharynx. However, LPR is associated with a distinct presentation of symptoms. LPR and GERD frequently differ in the relative prevalence of heartburn and throat clearing. While heartburn is present in over 80% of GERD cases, it occurs in only 20% of LPR cases. Throat clearing shows the opposite prevalence pattern, occurring in approximately 87% of LPR cases and in fewer than 5% of GERD cases. Unlike GERD, LPR also poses a risk for bronchitis or pneumonitis as reflux of stomach acid to the level of the larynx can result in aspiration. LPR is also commonly associated with erythema, or redness, as well as edema in the tissues of the larynx that are exposed to gastric contents. In contrast, most cases of GERD are nonerosive, with no apparent injury to the mucosal lining of the esophageal tissue exposed to the refluxed material.

Differences in the molecular structure of the epithelial tissue lining the laryngopharyngeal region may be partly responsible for the different symptomatic manifestations of LPR in comparison to GERD. In contrast to the resistant stratified squamous epithelium lining the esophagus, the larynx is lined by ciliated respiratory epithelium, which is more fragile and susceptible to damage. While the epithelium lining the esophagus is capable of withstanding as many as 50 instances of exposure to gastric contents each day, which is the uppermost estimate considered to be within the range of normal physiologic functioning, injury to laryngeal epithelium can occur following exposure to only small amounts of acidic gastric contents.

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.

Esophageal spasm or oesophageal spasm is a disorder of esophageal motility. The esophagus is an organ in vertebrates which consists of a fibromuscular tube through which food passes, aided by peristalsis contractions, from the upper esophageal sphincter to the stomach through waves of coordinated muscle contraction, or peristalsis.

There are two types of esophageal spasm:

- Diffuse esophageal spasm (DES), where there is uncoordinated esophageal contractions where several sections of the esophagus can contract at once.

- Nutcracker esophagus (NE) also known as hypertensive peristalsis, where the contractions are coordinated but with an excessive amplitude.

Both conditions can be linked with Gastroesophageal reflux disease (GERD).

When the coordinated muscle contraction are irregular or uncoordinated, this condition may be called diffuse esophageal spasm. These spasms can prevent food from reaching the stomach where food gets stuck in the esophagus. At other times the coordinated muscle contraction is very powerful, which is called nutcracker esophagus. These contractions move food through the esophagus but can cause severe pain.

Uterine tears often occur a few days post parturition. They can lead to peritonitis and require surgical intervention to fix. Uterine torsions can occur in the third trimester, and while some cases may be corrected if the horse in anesthetized and rolled, others require surgical correction.

Diaphragmatic hernias are rare in horses, accounting for 0.3% of colics. Usually the small intestine herniates through a rent in the diaphragm, although any part of the bowel may be involved. Hernias are most commonly acquired, not congenital, with 48% of horses having a history of recent trauma, usually through during parturition, distention of the abdomen, a fall, or strenuous exercise, or direct trauma to the chest. Congenital hernias occur most commonly in the most ventral part of the diaphragm, while acquired hernias are usually seen at the junction of the muscular and tendinous sections of the diaphragm. Clinical signs usually are similar to an obstruction, but occasionally decreased lung sounds may be heard in one section of the chest, although dyspnea is only seen in approximately 18% of horses. Ultrasound and radiography may both be used to diagnose diaphragmatic herniation.

Hiatal hernia has often been called the "great mimic" because its symptoms can resemble many disorders. Among them, a person with a hiatal hernia can experience dull pains in the chest, shortness of breath (caused by the hernia's effect on the diaphragm), heart palpitations (due to irritation of the vagus nerve), and swallowed food "balling up" and causing discomfort in the lower esophagus until it passes on to the stomach. In addition, hiatal hernias often result in heartburn but may also cause chest pain or pain with eating.

In most cases however, a hiatal hernia does not cause any symptoms. The pain and discomfort that a patient experiences is due to the reflux of gastric acid, air, or bile. While there are several causes of acid reflux, it occurs more frequently in the presence of hiatal hernia.

In newborns, the presence of Bochdalek hernia can be recognised from symptoms such as difficulty breathing fast respiration, increased heart rate.

The following are risk factors that can result in a hiatus hernia.

- Increased pressure within the abdomen caused by:

- Heavy lifting or bending over

- Frequent or hard coughing

- Hard sneezing

- Violent vomiting

- Straining

- Stress

Its main symptoms are pain and difficulty in swallowing (dysphagia).

Esophageal webs are thin (2-3mm) membranes of normal esophageal tissue consisting of mucosa and submucosa that can partially protrude/obstruct the esophagus. They can be congenital or acquired. Congenital webs commonly appear in the middle and inferior third of the esophagus, and they are more likely to be circumferential with a central or eccentric orifice. Acquired webs are much more common than congenital webs and typically appear in the cervical area (postcricoid).

Clinical symptoms of this condition are selective (solid more than liquids) dysphagia, thoracic pain, nasopharyngeal reflux, aspiration, perforation and food impaction (the last two are very rare).