The esophagus is the muscular tube that carries food and liquids from your mouth to the stomach. You may not be aware of your esophagus until you swallow something too large, too hot, or too cold. You may also notice it when something is wrong. You may feel pain or have trouble swallowing.

The most common problem with the esophagus is GERD (gastroesophageal reflux disease). With GERD, a muscle at the end of your esophagus does not close properly. This allows stomach contents to leak back, or reflux, into the esophagus and irritate it. Over time, GERD can cause damage to the esophagus.

Other problems include heartburn, cancer, and eosinophilic esophagitis. Doctors may use various tests to make a diagnosis. These include imaging tests, an upper endoscopy, and a biopsy.

Treatment depends on the problem. Some problems get better with over-the-counter medicines or changes in diet. Others may need prescription medicines or surgery.

The esophagus is a muscular tube that connects the pharynx to the stomach. It is approximately 25.4 cm (10 in) in length, located posterior to the trachea, and remains in a collapsed form when not engaged in swallowing. As you can see in image below, the esophagus runs a mainly straight route through the mediastinum of the thorax. To enter the abdomen, the esophagus penetrates the diaphragm through an opening called the esophageal hiatus.

Passage of Food through the Esophagus

The upper esophageal sphincter, which is continuous with the inferior pharyngeal constrictor, controls the movement of food from the pharynx into the esophagus. The upper two-thirds of the esophagus consists of both smooth and skeletal muscle fibers, with the latter fading out in the bottom third of the esophagus. Rhythmic waves of peristalsis, which begin in the upper esophagus, propel the bolus of food toward the stomach. Meanwhile, secretions from the esophageal mucosa lubricate the esophagus and food. Food passes from the esophagus into the stomach at the lower esophageal sphincter (also called the gastroesophageal or cardiac sphincter). Recall that sphincters are muscles that surround tubes and serve as valves, closing the tube when the sphincters contract and opening it when they relax. The lower esophageal sphincter relaxes to let food pass into the stomach, and then contracts to prevent stomach acids from backing up into the esophagus. Surrounding this sphincter is the muscular diaphragm, which helps close off the sphincter when no food is being swallowed. When the lower esophageal sphincter does not completely close, the stomach’s contents can reflux (that is, back up into the esophagus), causing heartburn or gastroesophageal reflux disease (GERD).

Histology of the Esophagus

The mucosa of the esophagus is made up of an epithelial lining that contains non-keratinized, stratified squamous epithelium, with a layer of basal and parabasal cells. This epithelium protects against erosion from food particles. The mucosa’s lamina propria contains mucus-secreting glands. The muscularis layer changes according to location: In the upper third of the esophagus, the muscularis is skeletal muscle. In the middle third, it is both skeletal and smooth muscle. In the lower third, it is smooth muscle. As mentioned previously, the most superficial layer of the esophagus is called the adventitia, not the serosa. In contrast to the stomach and intestines, the loose connective tissue of the adventitia is not covered by a fold of visceral peritoneum. The digestive functions of the esophagus are identified in image.

If you have a swallowing disorder, you may have difficulty or pain when swallowing. Some people cannot swallow at all. Others may have trouble swallowing liquids, foods, or saliva. This makes it hard to eat. Often, it can be difficult to take in enough calories and fluids to nourish your body.

Anyone can have a swallowing disorder, but it is more likely in the elderly. It often happens because of other conditions, including

• Nervous system disorders, such as Parkinson's disease and cerebral palsy
• Problems with your esophagus, including GERD (gastroesophageal reflux disease)
• Stroke
• Head or spinal cord injury
• Cancer of the head, neck, or esophagus

Medicines can help some people, while others may need surgery. Swallowing treatment with a speech-language pathologist can help. You may find it helpful to change your diet or hold your head or neck in a certain way when you eat. In very serious cases, people may need feeding tubes.

Your esophagus is the tube that carries food from your mouth to your stomach. Gastroesophageal reflux disease (GERD) happens when a muscle at the end of your esophagus does not close properly. This allows stomach contents to leak back, or reflux, into the esophagus and irritate it.

You may feel a burning in the chest or throat called heartburn. Sometimes, you can taste stomach fluid in the back of the mouth. If you have these symptoms more than twice a week, you may have GERD. You can also have GERD without having heartburn. Your symptoms could include a dry cough, asthma symptoms, or trouble swallowing.

Anyone, including infants and children, can have GERD. If not treated, it can lead to more serious health problems. In some cases, you might need medicines or surgery. However, many people can improve their symptoms by

• Avoiding alcohol and spicy, fatty or acidic foods that trigger heartburn
• Eating smaller meals
• Not eating close to bedtime
• Losing weight if needed
• Wearing loose-fitting clothes

Most of us get heartburn from time to time. It may come as a burning sensation in the chest, or a bitter taste in the back of the throat. Heartburn is one word people use to describe reflux. It happens when stomach contents come back upwards. Reflux is sometimes painless: You may have trouble swallowing or get a dry cough, perhaps some wheezing.

Occasional reflux episodes are normal. Like millions of Americans, you can manage reflux by avoiding foods that don’t agree with you—things that are fatty, spicy or acidic—or by eating smaller meals. If reflux occurs less than once a week, you can usually cope by making lifestyle changes or using over-the-counter medications.

“We all have a little reflux when we burp or belch,” says Dr. John Pandolfino of Northwestern University. But of the 20 million or more Americans with reflux, about 5% have significant episodes 2 or 3 times per day. When severe events occur this often, it’s not ordinary reflux. It may be gastroesophageal reflux disease (GERD). You may need prescription medications to control it.

GERD should be taken seriously. Stomach (gastric) contents contain acid needed to digest food. In reflux, these contents wash upward into the esophagus, a slender tube connecting the mouth and the stomach. Because the lining of the esophagus isn’t meant to touch gastric acid, the acid can irritate the lining of the esophagus and lead to bleeding and scarring. In adults, GERD can raise the risk of cancer of the esophagus. And if you have asthma, GERD can make it worse.

As for babies, reflux is common in healthy infants. Most babies outgrow reflux by 13 months, but if they don’t, they too may have GERD.

GERD can harm a child’s ability to feed and grow. It can also increase the risk for inhaling stomach contents into the lungs. This can be life-threatening.

People of any age can have GERD. Available medications, whether over-the-counter or prescription, can make the acid in the esophagus less intense. But medications don’t prevent GERD. Surgery can be an option if symptoms are severe and medicine and lifestyle changes don’t seem to help.

Dr. Michael Raymond Ruggieri, Sr., of Temple University is researching the root causes of GERD. The problem isn’t that the stomach makes too much acid. In GERD, the special set of muscles between the esophagus and the stomach is weakened.

“The stomach muscle fibers are not doing their job, and we’re trying to understand why they’re not,” says Dr. Ruggieri. His team is among the first to look at how nerves receive and send messages to these muscle fibers. Their goal is to develop drugs that prevent GERD altogether.

If you have reflux twice or more per week, talk to your health care provider. It’s best to start treatment early to prevent GERD from leading to more serious health problems.

How To Steer Clear of Reflux

• Maintain a healthy weight.
• Eat smaller meals.
• Avoid triggering foods, including alcohol.
• Don’t lie down for 3 hours after a meal.
• Raise the head of your bed 6 to 8 inches by putting wood blocks under the bedposts.
• For an infant, try burping frequently during feeding. Keep the infant upright for 30 minutes after feeding.
• If you have reflux twice or more per week, see your health care provider.

What is GER?

Gastroesophageal reflux (GER) happens when your stomach contents come back up into your esophagus. Many people have GER once in a while, and GER often happens without causing symptoms. In some cases, GER may cause heartburn, also called acid indigestion.

Does GER have another name?

Doctors also refer to GER as

• acid indigestion
• acid reflux
• acid regurgitation
• heartburn
• reflux

How common is GER?

Having GER once in a while is common.

What is GERD?

Gastroesophageal reflux disease (GERD) is a more severe and long-lasting condition in which GER causes repeated symptoms that are bothersome or leads to complications over time.

If you think you may have GERD, you should see your doctor.

How common is GERD?

Researchers estimate that about 20 percent of people in the United States have GERD.

Who is more likely to have GERD?

Anyone can develop GERD. You are more likely to have GERD if you

• are overweight or have obesity
• are a pregnant woman
• take certain medicines
• smoke or are regularly exposed to secondhand smoke

The esophagus is a hollow tube that carries food and liquids from your throat to your stomach. Early esophageal cancer usually does not cause symptoms. Later, you may have symptoms such as:

• Painful or difficult swallowing
• Weight loss
• A hoarse voice or cough that doesn't go away

You're at greater risk for getting esophageal cancer if you smoke, drink heavily, or have acid reflux. Your risk also goes up as you age.

Your doctor uses imaging tests and a biopsy to diagnose esophageal cancer. Treatments include surgery, radiation, and chemotherapy. You might also need nutritional support, since the cancer or treatment may make it hard to swallow.

General Information About Esophageal Cancer

KEY POINTS

• Esophageal cancer is a disease in which malignant (cancer) cells form in the tissues of the esophagus.
• Smoking, heavy alcohol use, and Barrett esophagus can increase the risk of esophageal cancer.
• Signs and symptoms of esophageal cancer are weight loss and painful or difficult swallowing.
• Tests that examine the esophagus are used to diagnose esophageal cancer.
• Certain factors affect prognosis (chance of recovery) and treatment options.

Esophageal cancer is a disease in which malignant (cancer) cells form in the tissues of the esophagus.

The esophagus is the hollow, muscular tube that moves food and liquid from the throat to the stomach. The wall of the esophagus is made up of several layers of tissue, including mucous membrane, muscle, and connective tissue. Esophageal cancer starts on the inside lining of the esophagus and spreads outward through the other layers as it grows.

The two most common forms of esophageal cancer are named for the type of cells that become malignant (cancerous):

• Squamous cell carcinoma: Cancer that forms in the thin, flat cells lining the inside of the esophagus. This cancer is most often found in the upper and middle part of the esophagus, but can occur anywhere along the esophagus. This is also called epidermoid carcinoma.
• Adenocarcinoma: Cancer that begins in glandular cells. Glandular cells in the lining of the esophagus produce and release fluids such as mucus. Adenocarcinomas usually form in the lower part of the esophagus, near the stomach.

The Human Digestive System

The process of digestion begins in the mouth with the intake of food (Figure below). The teeth play an important role in masticating (chewing) or physically breaking food into smaller particles. The enzymes present in saliva also begin to chemically break down food. The food is then swallowed and enters the esophagus—a long tube that connects the mouth to the stomach. Using peristalsis, or wave-like smooth-muscle contractions, the muscles of the esophagus push the food toward the stomach. The stomach contents are extremely acidic, with a pH between 1.5 and 2.5. This acidity kills microorganisms, breaks down food tissues, and activates digestive enzymes. Further breakdown of food takes place in the small intestine where bile produced by the liver, and enzymes produced by the small intestine and the pancreas, continue the process of digestion. The smaller molecules are absorbed into the blood stream through the epithelial cells lining the walls of the small intestine. The waste material travels on to the large intestine where water is absorbed and the drier waste material is compacted into feces; it is stored until it is excreted through the anus.

Figure. The components of the human digestive system are shown.

Digestive Processes

The processes of digestion include six activities: ingestion, propulsion, mechanical or physical digestion, chemical digestion, absorption, and defecation.

The first of these processes, ingestion, refers to the entry of food into the alimentary canal through the mouth. There, the food is chewed and mixed with saliva, which contains enzymes that begin breaking down the carbohydrates in the food plus some lipid digestion via lingual lipase. Chewing increases the surface area of the food and allows an appropriately sized bolus to be produced.

Food leaves the mouth when the tongue and pharyngeal muscles propel it into the esophagus. This act of swallowing, the last voluntary act until defecation, is an example of propulsion, which refers to the movement of food through the digestive tract. It includes both the voluntary process of swallowing and the involuntary process of peristalsis. Peristalsis consists of sequential, alternating waves of contraction and relaxation of alimentary wall smooth muscles, which act to propel food along (Figure). These waves also play a role in mixing food with digestive juices. Peristalsis is so powerful that foods and liquids you swallow enter your stomach even if you are standing on your head.

Figure. Peristalsis - Peristalsis moves food through the digestive tract with alternating waves of muscle contraction and relaxation.

Digestion includes both mechanical and chemical processes. Mechanical digestion is a purely physical process that does not change the chemical nature of the food. Instead, it makes the food smaller to increase both surface area and mobility. It includes mastication, or chewing, as well as tongue movements that help break food into smaller bits and mix food with saliva. Although there may be a tendency to think that mechanical digestion is limited to the first steps of the digestive process, it occurs after the food leaves the mouth, as well. The mechanical churning of food in the stomach serves to further break it apart and expose more of its surface area to digestive juices, creating an acidic “soup” called chyme. Segmentation, which occurs mainly in the small intestine, consists of localized contractions of circular muscle of the muscularis layer of the alimentary canal. These contractions isolate small sections of the intestine, moving their contents back and forth while continuously subdividing, breaking up, and mixing the contents. By moving food back and forth in the intestinal lumen, segmentation mixes food with digestive juices and facilitates absorption.

In chemical digestion, starting in the mouth, digestive secretions break down complex food molecules into their chemical building blocks (for example, proteins into separate amino acids). These secretions vary in composition, but typically contain water, various enzymes, acids, and salts. The process is completed in the small intestine.

Food that has been broken down is of no value to the body unless it enters the bloodstream and its nutrients are put to work. This occurs through the process of absorption, which takes place primarily within the small intestine. There, most nutrients are absorbed from the lumen of the alimentary canal into the bloodstream through the epithelial cells that make up the mucosa. Lipids are absorbed into lacteals and are transported via the lymphatic vessels to the bloodstream (the subclavian veins near the heart). The details of these processes will be discussed later.

In defecation, the final step in digestion, undigested materials are removed from the body as feces.

In some cases, a single organ is in charge of a digestive process. For example, ingestion occurs only in the mouth and defecation only in the anus. However, most digestive processes involve the interaction of several organs and occur gradually as food moves through the alimentary canal (Figure below).

Figure. Digestive Processes - The digestive processes are ingestion, propulsion, mechanical digestion, chemical digestion, absorption, and defecation.

The esophagus is a tubular organ that connects the mouth to the stomach. The chewed and softened food passes through the esophagus after being swallowed. The smooth muscles of the esophagus undergo peristalsis that pushes the food toward the stomach. The peristaltic wave is unidirectional—it moves food from the mouth the stomach, and reverse movement is not possible, except in the case of the vomit reflex. The peristaltic movement of the esophagus is an involuntary reflex; it takes place in response to the act of swallowing.

Ring-like muscles called sphincters form valves in the digestive system. The gastro-esophageal sphincter (or cardiac sphincter) is located at the stomach end of the esophagus. In response to swallowing and the pressure exerted by the bolus of food, this sphincter opens, and the bolus enters the stomach. When there is no swallowing action, this sphincter is shut and prevents the contents of the stomach from traveling up the esophagus. Acid reflux or “heartburn” occurs when the acidic digestive juices escape into the esophagus.

Figure. (a) Digestion of food begins in the mouth. (b) Food is masticated by teeth and moistened by saliva secreted from the salivary glands. Enzymes in the saliva begin to digest starches and fats. With the help of the tongue, the resulting bolus is moved into the esophagus by swallowing. (credit: modification of work by Mariana Ruiz Villareal)

The esophagus is a muscular tube about ten inches (25 cm.) long, extending from the hypopharynx to the stomach. The esophagus lies posterior to the trachea and the heart and passes through the mediastinum and the hiatus, an opening in the diaphragm, in its descent from the thoracic to the abdominal cavity. The esophagus has no serosal layer; tissue around the esophagus is called adventitia.

There are two sub site descriptions for the esophagus and they are not equivalent.

Sub Site Description 1

Cervical

• Cervical begins at the lower end of pharynx (level of 6th vertebra or lower border of cricoid cartilage) and extends to the thoracic inlet (suprasternal notch); 18 cm from incisors.

Thoracic

• Upper thoracic: from thoracic inlet to level of tracheal bifurcation; 18-23 cm.
• Mid thoracic: from tracheal bifuraction midway to gastroesophageal junction; 24-32 cm.
• Lower thoracic: from midway between tracheal bifurcation and gastroesophageal junction to GE junction, including abdominal esophagus; 32-40 cm.

Abdominal

• Considered part of lower thoracic esophagus; 32-40 cm.

Sub Site Description 2

• Upper third (10% of esophageal cancers)
• Middle third (40%)
• Lower third (50%)

The figure below illustrates the correlation between sub site descriptions of the esophagus.

Eosinophilic esophagitis (EoE) is a chronic disease of the esophagus. Your esophagus is the muscular tube that carries food and liquids from your mouth to the stomach. If you have EoE, white blood cells called eosinophils build up in your esophagus. This causes damage and inflammation, which can cause pain and may lead to trouble swallowing and food getting stuck in your throat.

EoE is rare. But because it is a newly recognized disease, more people are now getting diagnosed with it. Some people who think that they have reflux (GERD) may actually have EoE.

INFLAMMATION, acute or chronic, of the ESOPHAGUS caused by BACTERIA, chemicals, or TRAUMA.