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Anorexia nervosa, bulimia - medical causes of eating disorders - symptoms, treatment, diagnosis
Medical Disorders And Conditions That Can Cause Anorexia, Weight Loss, Or Vomiting

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Defining the Terminology | Diagnostic Criteria | The Author Tells His Story | More Misdiagnosis Cases | A Quick Overview of the Genesis of Anorexia Nervosa | Medical Disorders And Conditions That Can Cause Anorexia, Weight Loss, Or Vomiting | Medical Tests | Diagnostic Deficiencies | A Message To Parents | A Message to Physicians | A Message to Therapists | A Quick Lesson on Human Nature | A Skeptical Look at the Conventional Wisdom | Public Awareness Campaigns Backfire | Depression and Anorexia | Classical Conditioning and Anorexia | Obsessive Compulsive Disorder | Excessive Exercise | Perfectionism | Sexual Abuse and Anorexia | Laxative Abuse | Bulimia Nervosa | Starvation Response | Malabsorption and Weight Loss | Body Mass Index : A Flawed Concept? | The Anorexic Voice | Art Therapy | Pro-Anorexia Web Sites | Celebrity Role Models | How Belief Skews Perception | Vegetarianism and Anorexia | Disturbing Trends in Medicine | Eating Disorder Clinics - Medical Testing | Frequently Asked Questions | About the Author | Contact Us | Bibliography | Disclaimer | The Future of Eating Disorders

 
Anorexia (loss of appetite), weight loss, and vomiting can be presenting symptoms of many diseases. If the disease is a chronic disorder, then the patient may not even be aware that something is wrong, since they often gradually adapt to the condition. Since so many young women are dieting and exercising, it is easy to assume that excessive weight loss or habitual vomiting is a choice of the patient; when in fact it may be a consequence of disease.
 
Some of these disorders are easily diagnosed; however, there is a distinct possibility that patients with these conditions may end up in eating disorder programs where the underlying medical condition will not be addressed. Public awareness of eating disorders is high, and since few public awareness campaigns have mentioned medical illness being a cause of anorexia or vomiting, a young person experienceing nausea or anorexia may be quite secretive about it, fearing they have a psychiatric disorder. If appropriate diagnostic testing is not performed, the underlying disorder may be missed. 
 
Listed below are several chronic conditions that may cause anorexia, weight loss, or vomiting.
 
Chronic Cholecystitis:  Inflammation of the gallbladder. This may or may not be caused by gallstones. Acalculous (no gallstones) cholecystitis can give many of the same symptoms as having gallstones. Some individuals may have a cystic bile duct that is small or kinks, resulting in stagnation and concentration of bile, causing chemical irritation of the gallbladder walls. Some individuals may have have a low gallbladder ejection fraction which may lead to inflammation and poor digestion and absorption. Bacterial infection of the bile may ensue.
 
Presenting symptoms may include vague abdominal pain, indigestion, nausea, anorexia, flatulence, constipation, jaundice, belching, and fatty food intolerance. This medical condition should be highly suspected in both anorexic and bulimic individuals. Why some patients develop anorexia while others vomit after meals is an area future research should focus on (see page on research suggestions). Personality, degree of inflammation, and many other factors may affect outcomes.
 
Cholelithiasis: 

Most clinical disorders of the extrahepatic biliary tract are related to gallstones. In the USA, 20% of persons > age 65 have gallstones, and each year > 500,000 undergo cholecystectomy. Factors that increase the probability of gallstones include female sex, obesity, increased age, North American Indian ethnicity, a Western diet, and a positive family history

Cholesterol, the major component of most gallstones, is highly insoluble in water, and biliary cholesterol is solubilized in bile salt-phospholipid micelles and phospholipid vesicles, which greatly increase the cholesterol-carrying capacity of bile. Bile salt micelles are aggregates of bile salts in which water-soluble (ionic) regions of the molecule face outward into aqueous solution, while the water-insoluble (nonpolar) steroid nuclei face inward. Cholesterol is soluble inside these spheroid micelles, and their cholesterol-carrying ability is further enhanced by lecithin, a polar phospholipid. The amount of cholesterol carried in micelles and vesicles varies with the bile salt secretion rate.

Supersaturation of cholesterol in bile is a necessary condition, but not a sole cause, of cholesterol gallstone formation because supersaturation is frequent in the bile of fasting persons without gallstones. The other critical factor in determining whether gallstones form is regulation of the initiating process, cholesterol monohydrate crystal formation. In gallbladder bile that is lithogenic (ie, prone to stone formation), there is supersaturation of cholesterol and relatively rapid nucleation of cholesterol crystals. The dynamic interplay of forces for and against cholesterol crystal nucleation and growth in the gallbladder includes the actions of specific proteins or apoproteins, gallbladder mucin, and gallbladder stasis.

Virtually all gallstones form within the gallbladder, but stones may form in the bile duct after cholecystectomy or behind strictures as a result of stasis.

The clinical consequences of stone formation in the gallbladder are exceedingly variable. Most patients remain asymptomatic for long periods, frequently for life. Stones may traverse the cystic duct with or without symptoms of obstruction. Transient cystic duct obstruction results in colicky pain, whereas persistent obstruction usually produces inflammation and acute cholecystitis. In contrast to other types of colic, biliary colic typically is constant, with pain progressively rising to a plateau and falling gradually, lasting up to several hours. Nausea and vomiting are often associated. Fever and chills are absent in uncomplicated gallbladder colic. Pain most often occurs in the epigastrium or right upper quadrant, radiating to the right lower scapula.

Symptoms of dyspepsia and fatty food intolerance are often inaccurately ascribed to gallbladder disease. Belching, bloating, fullness, and nausea are associated about equally with cholelithiasis, peptic ulcer disease, or functional distress. Such symptoms may disappear after cholecystectomy but should not be the only indication for operation. Postprandial fatty food intolerance is likely to be caused by cholelithiasis if symptoms include right upper quadrant pain; however, the prevalence of postprandial functional distress is so high in the general population that symptoms alone are insufficient for diagnosis of gallbladder disease without supportive clinical signs and diagnostic studies. This condition should be highly suspected in both anorexic and bulimic individuals.

Peptic Ulcer Disease: Peptic ulcer disease (PUD) affects the stomach, esophagus or, more usually, the duodenum. In fact, duodenal ulcers are four times more likely to occur than gastric ulcers (stomach ulcers). Peptic ulcers are a very common occurrence affecting 10% of men and 5% of women in the U.S. during their lifetimes, though women tend to be more affected by duodenal ulcers than ulcers of the stomach or esophagus.

Some patients do not present with symptoms except for a mild epigastric tenderness, but most patients experience (no matter where the ulcer is located) pain in the area of the upper abdomen, varying in intensity from patient to patient, and variously described as dull, boring, burning, or gnawing. The pain is usually experienced on an empty stomach, a few hours after meals and is often relieved by food or by taking antacids. Sometimes the patient may be awakened by pain, especially late at night, that can radiate to the back. Patients may also experience gastrointestinal bleeding (often the first sign), abdominal bloating, nausea, vomiting, anorexia and weight loss (usually in patients with outflow obstruction).

Gastroesophogeal Reflux Disease: GERD is a complex disorder with diverse symptoms that are often suggestive of a number of other, sometimes more serious, diseases.  Patients may present with a broad range of typical and atypical symptoms, and a conclusive diagnosis of GERD can be difficult.  Heartburn, chest pain, dysphagia, chronic cough, asthma, chronic bronchitis or laryngitis, early satiety, and/or nausea, bloating,  anorexia, and weight loss are common symptoms in adults. Infants and children often present with recurrent vomiting, coughing, breathing problems, or a failure to thrive.

Crohn's Disease: Crohn's disease causes inflammation in the small intestine. Crohn's disease usually occurs in the lower part of the small intestine, called the ileum, but it can affect any part of the digestive tract, from the mouth to the anus. The inflammation extends deep into the lining of the affected organ. The inflammation can cause pain and can make the intestines empty frequently, resulting in diarrhea.

Crohn's disease is an inflammatory bowel disease (IBD), the general name for diseases that cause inflammation in the intestines. Crohn's disease can be difficult to diagnose because its symptoms are similar to other intestinal disorders such as irritable bowel syndrome and to another type of IBD called ulcerative colitis. Ulcerative colitis causes inflammation and ulcers in the top layer of the lining of the large intestine.

Crohn's disease affects men and women equally and seems to run in some families. About 20 percent of people with Crohn's disease have a blood relative with some form of IBD, most often a brother or sister and sometimes a parent or child. Crohn's disease may also be called ileitis or enteritis.

The most common symptoms of Crohn's disease are abdominal pain, often in the lower right area, and diarrhea. Rectal bleeding, anorexia, weight loss, and fever may also occur. Bleeding may be serious and persistent, leading to anemia. Children with Crohn's disease may suffer delayed development and stunted growth.

Superior Mesenteric Artery Syndrome

Superior mesenteric artery (SMA) syndrome is a rare but well recognized clinical entity characterized by compression of the third, or transverse, portion of the duodenum against the aorta by the SMA, resulting in chronic, intermittent, or acute complete or partial duodenal obstruction.

Patients often present with chronic upper abdominal symptoms such as epigastric pain, nausea, eructation, voluminous vomiting (bilious or partially digested food), postprandial discomfort, early satiety, and sometimes as subacute small bowel obstruction. The symptoms typically are relieved when the patient is in the left lateral decubitus, prone, or knee-chest positions, and they often are aggravated when the patient is in the supine position. The condition can also cause anorexia and weight loss.

Diabetes Mellitus

Most of the food we eat is turned into glucose, or sugar, for our bodies to use for energy. The pancreas, an organ that lies near the stomach, makes a hormone called insulin to help glucose get into the cells of our bodies. When you have diabetes, your body either doesn't make enough insulin or can't use its own insulin as well as it should. This causes sugars to build up in your blood.

Symptoms may include frequent urination, excessive thirst, unexplained weight loss, extreme hunger, sudden vision changes, tingling or numbness in hands or feet, feeling very tired much of the time,very dry skin, sores that are slow to heal, more infections than usual. Nausea, vomiting, or stomach pains may accompany some of these symptoms in the abrupt onset of insulin-dependent diabetes.

The two main tests used to diagnose diabetes are the fasting blood glucose test and the oral glucose tolerance test.

Addison's Disease

Addison's disease is a rare endocrine or hormonal disorder that affects about 1 in 100,000 people. It occurs in all age groups and afflicts men and women equally. The disease is characterized by weight loss, muscle weakness, fatigue, low blood pressure, and sometimes darkening of the skin in both exposed and nonexposed parts of the body.

Addison's disease occurs when the adrenal glands do not produce enough of the hormone cortisol and in some cases, the hormone aldosterone. For this reason, the disease is sometimes called chronic adrenal insufficiency, or hypocortisolism.

For an interesting article on adrenal insufficiency and it's possible role in eating disorders, click here.

Pregnancy

Hormonal changes associated with pregnancy may cause nausea and vomiting, and subsequent initial weight loss. Hyperemesis gravidum is excessive vomiting during pregnancy. Affecting 1 in 300 women, the vomiting is persistent, frequent and severe. Most commonly, the severe vomiting occurs during pregnancy weeks 8 to 20. Severe nausea and vomiting can cause dehydration in the mother and disrupts her electrolyte balance. The exact cause of hyperemesis gravidum is unknown, but it appears to be related to unusually high levels of the hormones estrogen and human chorionic gonadotropin. Hence, excessive vomiting is more common in multiple pregnancies since hormonal levels are higher than in single pregnancies. Hyperemesis gravidum is also more common in first pregnancies and among obese women.

I doubt that any competent doctor would misdiagnose a pregnant women as having AN or BN, however, the possibility is there if a pregnancy test is not performed. My wife's weight dropped from 120 lbs to 100 lbs (5'-7" tall) during her first 3 months of pregnancy due to nausea and vomiting. She was hospitalized several times during the pregnancy due to this disorder. When the hyperemisis gravidum finally subsided, she began to eat normally and reached 152 lbs. by the time she gave birth to our daughter. 

Post Nasal Drip

When the nasal passages are irritated by allergies, air pollution, smoke, or viral infections (such as a "cold"), then the nose and sinus membranes secrete more than the normal amount of mucus. This will be a clear, watery, and profuse mucus that is supposed to wash away the irritation or allergy. This is the most common type of "post-nasal drip." Another form of "post-nasal drip" is mucus that is thick and sticky. This occurs when the air is too dry and the nose membranes cannot produce enough moisture to put into the mucus for it to flow easily. Bacterial infections also produce a thick, sticky mucus with pus in it, turning it a yellow or green color.

Thick, often very sweet, mucus can collect in the esophagus and cause vomiting after meals, especially in the early morning. Individuals with post nasal drip may choose to skip breakfast to avoid the annoying vomiting that ensues after eating. This condition, if not recognized, may be incorrectly interpreted as purging behavior associated with bulimia nervosa.

Hepatitis

Hepatitis is a general term that refers to inflammation of the liver. This condition may result from various infectious and noninfectious etiologies. Infectious etiologies include viral, bacterial, fungal, and parasitic organisms. Medications, toxins, and autoimmune disorders may cause noninfectious hepatitis.

Symptoms are similar to flu, but the skin and the eyes may become yellow (icterus) because the liver is not able to filter bilirubin from the blood. Other symptoms can include anorexia, weight loss, nausea, vomiting, fever, body pains, pale or clay colored stool, dark urine, itching.

When most people refer to hepatitis, they are probably talking about viral hepatitis, which is classified into several types. Hepatitis A, which is very common in underdeveloped countries, is acquired from water or food sources. This type of hepatitis is usually mild and may sometimes be discovered only by blood testing. Hepatitis A never leads to chronic liver disease.

The hepatitis B virus is most often contracted via blood contact -- such as with IV drug abusers sharing needles or health care workers who are stuck by tainted needles. It can also be spread via sexual contact and from mother to baby during childbirth. Hepatitis B can lead to chronic liver disease and the complications that result from it.

Hepatitis C is spread via blood and body-fluid contact (as with Hepatitis B). Hepatitis C used to be the most common type of hepatitis acquired via blood transfusions until a test for it became available in the 1980s. Hepatitis C commonly leads to chronic hepatitis and over many years can lead to chronic liver disease manifested by cirrhosis.

Other much less common types of viral hepatitis include hepatitis D (which is seen most commonly in IV drug abusers and which requires co-infection with hepatitis B), hepatitis E (seen in pregnant women and spread in a similar fashion to hepatitis A) and hepatitis G (commonly seen in patients who are undergoing hemodialysis). It is speculated that other types of viral hepatitis have yet to be identified.

HIV / Aids

Weight loss is a common complaint of individuals with HIV infection and AIDS. The Centers for Disease Control (CDC) defines wasting syndrome as an unexplained weight loss greater than 10% from baseline or ideal body weight in conjunction with constitutional symptoms lasting one month or longer.

Wasting can occur because of inadequate intake due to anorexia (poor appetite) and fatigue resulting from disease or medications. Given this scenario, a vicious cycle can occur in the seriously debilitated person as malnutrition often produces these very same symptoms. Thus the individual becomes increasingly malnourished because he/she has no appetite to eat or limited energy to purchase and prepare food.

Research studies have shown that individuals with acute or chronic infection often have elevated basal metabolic rates and therefore will require increased calorie and protein intake. Individuals with AIDS who have active disease are no exceptions. There are data however, suggesting that unless the underlying infection is treated, increasing intake will have little effect on increasing lean body mass. A study in patients with cytomegalovirus or mycobacterium avium complex disease showed that they continued to lose lean body mass despite nutritional repletion until they began appropriate antiviral or antimycobacterial therapy. Therefore, immunocompromised HIV infected individuals who begin to lose weight should be carefully evaluated for infection or malignancy and appropriate therapy implemented in conjunction with a program aimed at nutritional repletion.

Sexually Transmitted Diseases

The incidence of sexually transmitted diseases (STDs), among the most common communicable diseases in the world, steadily increased from the 1950s to the 1970s but generally stabilized in the 1980s. The incidence of some diseases (eg, syphilis and gonorrhea) decreased from the mid-1980s to the mid-1990s in the USA and elsewhere. Nonspecific urethritis, trichomoniasis, chlamydial infections, genital and anorectal herpes and warts, scabies, pediculosis pubis, and molluscum contagiosum are probably more prevalent than the five historically defined venereal diseases--syphilis, gonorrhea, chancroid, lymphogranuloma venereum, and granuloma inguinale. However, because the latter diseases are more consistently reported, reliable incidence rates for the others are not available.

In 1995, worldwide incidence of gonorrhea was estimated at > 250 million cases (USA, about 400,000); for syphilis, 50 million cases (USA, about 70,000, including about 16,000 primary and secondary cases and 1,500 congenital cases). Chlamydial STDs now approach 1/2 million reported cases annually in the USA, but only an estimated 10 to 20% of all cases are reported. Other infections, including salmonellosis, giardiasis, amebiasis, shigellosis, campylobacteriosis, hepatitis A and B, and cytomegalovirus infection, are transmitted sexually but also by other routes. A strong association between cervical cancer and sexually transmitted papillomaviruses exists. Since 1978, HIV has spread rapidly among various populations. STD's may account for the higher incidence of eating disorders among homosexual men.

STD's should be ruled out by diagnostic testing, since several of them may present with nausea, vomiting, or anorexia and weight loss.

Parasitic Infections

The most common symptom of parasite infection is diarrhea, with abdominal pain as the second most common symptom. Other symptoms include flatulence, foul-smelling stools, cramps, distention, anorexia, nausea, weight loss, belching, heartburn, headache, constipation, vomiting, fever, chills, bloody stools, mucus in stools, and fatigue. Although specific symptoms are associated with certain organisms (e.g. fever with malaria), most symptoms can be present with almost any parasite.

Since travelling to exotic locations is becoming more common, the possibility of parasitic infection should be considered. It is not uncommon for tourists travelling in developing countries to be infected with parasites, resulting in chronic infection. 

Cancer

Many cancers can cause anorexia, weight loss, nausea and vomiting; indigestion or heartburn; discomfort or pain in the abdomen, diarrhea or constipation; bloating after meals; weakness and fatigue.

Ulcerative Colitis

Ulcerative colitis is a disease that causes inflammation and sores, called ulcers, in the top layers of the lining of the large intestine. The inflammation usually occurs in the rectum and lower part of the colon, but it may affect the entire colon. Ulcerative colitis rarely affects the small intestine except for the lower section, called the ileum. Ulcerative colitis may also be called colitis, ileitis, or proctitis.

The most common symptoms of ulcerative colitis are abdominal pain and bloody diarrhea. Patients also may experience fatigue, anorexia, weight loss, rectal bleeding, and loss of body fluids and nutrients.

Intestinal Obstruction

Intestinal obstruction involves a partial or complete blockage of the bowel that results in the failure of the intestinal contents to pass through.

 Obstruction of the bowel may be caused by ileus, in which the bowel doesn't function correctly but there is no mechanical (anatomic) problem, or by mechanical causes. Paralytic ileus, also called pseudo-obstruction, is one of the major causes of obstruction in infants and children.

The causes of paralytic ileus may include medications, intraperitoneal infection, mesenteric ischemia (decreased blood supply to the support structures in the abdomen), injury to the abdominal blood supply, complications of intra-abdominal surgery, kidney or thoracic disease, metabolic disturbances (such as decreased potassium levels)

Paralytic ileus may lead to complications causing jaundice and electrolyte imbalances. In older children, gastroenteritis may be a cause of paralytic ileus, which is sometimes associated with peritonitis and a ruptured appendix.

Mechanical obstruction occurs when movement of material through the intestines is physically blocked. The mechanical causes of obstruction are numerous and may include hernias, postoperative adhesions or scar tissue, impacted feces (stool), gallstones, tumors blocking the intestines, granulomatous processes (abnormal tissue growth), intussusception, volvulus (twisted intestine), or foreign bodies (ingested materials that obstruct the intestines).

Symptoms can include abdominal fullness, gaseousness, abdominal distention, abdominal pain and cramping, anorexia, weight loss, vomiting, constipation, diarrhea, and breath odor.

Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a digestive disorder that causes abdominal pain, bloating, gas, diarrhea, and constipation--or some combination of these problems. IBS affects people of all ages, including children.

IBS is classified as a functional disorder because it is caused by a problem in how the intestines, or bowels, work. People with IBS tend to have overly sensitive intestines that have muscle spasms in response to food, gas, and sometimes stress. These spasms may cause pain, diarrhea, and constipation. In children, IBS tends to be either diarrhea-predominant or pain-predominant. Diarrhea-predominant IBS is most common in children under age 3. The diarrhea is usually painless and alternates with bouts of constipation.

These children usually have fewer than five stools a day, and the stools tend to be watery and soft. Pain-predominant IBS mainly affects children over age 5. In the younger children the pain tends to occur around the navel area, and in older children, in the lower left part of the abdomen. The pain is crampy and gets worse with eating and better after passing stool or gas.

In addition to the symptoms described above, children with IBS may also have headache, nausea, or mucus in the stool. Weight loss may occur if a child eats less to try to avoid pain. Some children first develop symptoms after a stressful event, such as teething, a bout with the flu, school problems, or problems at home. Stress does not cause IBS, but it can trigger symptoms

Carbohydrate Intolerance

Diarrhea and abdominal distention caused by an inability to digest carbohydrates because of a lack of one or more intestinal enzymes.

Symptoms and signs are similar with all enzyme deficiencies. A child who cannot tolerate lactose will have diarrhea after ingesting milk and will not gain weight. An adult may have borborygmi, bloating, flatus, nausea, diarrhea, and abdominal cramps after eating lactose-containing food. Even diarrhea associated with lactose intolerance (caused by lactase deficiency) may be severe enough to purge other nutrients before they can be absorbed. A history of intolerance to dairy foods may be obtained from these patients, who may recognize this early in life and avoid eating dairy products. Symptoms may simulate the irritable bowel syndrome.

Celiac Disease

Celiac disease is a digestive disease that damages the small intestine and interferes with absorption of nutrients from food. People who have celiac disease cannot tolerate a protein called gluten, which is found in wheat, rye, barley, and possibly oats. When people with celiac disease eat foods containing gluten, their immune system responds by damaging the small intestine. Specifically, tiny fingerlike protrusions, called villi, on the lining of the small intestine are lost. Nutrients from food are absorbed into the bloodstream through these villi. Without villi, a person becomes malnourished, regardless of the quantity of food eaten.

Symptoms may or may not occur in the digestive system. For example, one person might have diarrhea and abdominal pain, while another person has irritability or depression. In fact, irritability is one of the most common symptoms in children.

Symptoms of celiac disease may include recurring abdominal bloating and pain, chronic diarrhea, weight loss; pale, foul-smelling stool, unexplained anemia (low count of red blood cells), gas, bone pain, behavior changes, muscle cramps, fatigue, delayed growth, failure to thrive, tooth discoloration or loss of enamel, missed menstrual periods (often because of excessive weight loss).

Some people with celiac disease may not have symptoms. The undamaged part of their small intestine is able to absorb enough nutrients to prevent symptoms. However, people without symptoms are still at risk for the complications of celiac disease.

Tropical Sprue

An acquired disease of unknown etiology characterized by malabsorption, multiple nutritional deficiencies, and mucosal abnormalities in the small bowel.

Tropical sprue occurs chiefly in the Caribbean, south India, and Southeast Asia, affecting both natives and visitors. Suggested causes are bacterial, viral, or parasitic infection, vitamin deficiency (especially folic acid), or food toxin (eg, in rancid fats). It can be acquired by tourists travelling in these areas.

Diarrhea is the main symptom of tropical sprue; people on high-fat diets may experience more severe diarrhea than those on diets low in fat. Other symptoms include cramps, weight loss, gas and indigestion.

Infections

Acute bacterial and viral infections may cause transient malabsorption, probably as a result of temporary, superficial damage to the villi and microvilli. Chronic bacterial infections of the small bowel are uncommon, apart from blind loops, scleroderma, and diverticula. Intestinal bacteria may use up dietary vitamin B12, perhaps interfere with enzyme systems, and cause superficial inflammation. Strep infections have been known to cause anorexia and vomiting and should be ruled out by diagnostic testing.

Oral Contraceptives and HRT

Nausea is a common side effect of oral contraceptives and hormone replacement therapy. High estrogen levels are commonly associated with nausea, and can seriously impact appetite. If nausea is prolonged, significant unintentional weight loss may ensue due to reduced caloric intake.

Users of birth control pills have a greater risk of developing gallbladder disease requiring surgery within the first year of use  (see cholecystitis and cholelithiasis, above). Other side effects include liver problems with jaundice (yellowing of the skin). The short and long-term use of birth control pills has also been linked with the growth of liver tumours.

Medications

Some medications have side effects that may include anorexia, nausea and vomiting, or food cravings. The possibility of medication playing a role in eating behavior should not be dismissed.

Poisoning

Exposure to toxic chemicals can result in anorexia, nausea, weight loss and vomiting.

Dental Appliances

When braces are fitted and periodically adjusted, the teeth loosen and migrate. This can cause pain as the teeth drift into their new position. It may be difficult to bite and/or chew certain foods during orthodontic treatment. In fact, biting into whole apples and chewing hard and/or sticky food is discouraged while a patient is wearing braces.

Braces and retainers are more commonly fitted to girls than boys, due mainly to heightened concerns with appearance among females. If dental appliances cause pain or alter taste sensations, they may reduce the pleasure associated with eating and thus have a negative impact on appetite. Future research should explore the relationship of dental appliances to weight loss. 

Dental Surgery

Some dental surgeries can leave the patient with sores in their mouth that make eating difficult. Unintentional weight loss may ensue if conscious efforts are not made to ensure sufficient caloric intake. My wife's weight dropped from 130 lbs. to 110 lbs. (5'-7" tall) in the weeks following wisdom tooth extraction, due to painful sores and ulcers in her mouth that made eating difficult. The role of oral pain must not be discounted in cases of unintentional weight loss.

Further Reading

Even though an anorexic patient may profess to want to lose weight, extreme weight loss may be due to a medical disorder. In such cases, the physician is wise to use the same diagnostic procedures as for diagnosing unintentional weight loss. An excellent article written by physicians at Mayo Clinic discusses this problem. Click here to view the article. 

It cannot be overemphasized that any of the disorders or conditions listed above are most likely to cause dangerous unintentional weight loss mainly in athletes, dancers, or dieting individuals, since they may already be experiencing a caloric deficit and low body fat stores due to their eating and exercise regimen. If these disorders are left undiagnosed and untreated, the patient may still attempt to maintain their exercise regimen despite reduced appetite or absorption. 

Conclusion

The medical disorders and conditions listed above are just a few of many that must be ruled out before a diagnosis of Anorexia Nervosa or Bulimia Nervosa can be made, even though the patient may meet all the diagnostic criteria set out in DSM-IV. The presence or absence of disease must be determined by appropriate physical examination and diagnostic testing. The attending physician and therapist must never assume that anorexia, excessive weight loss, failure to thrive, or chronic vomiting is due to a psychiatric disorder.