In some instances, the abnormal function can be demonstrated by tests (for example, gastric emptying studies or antro-duodenal motility studies). However, the tests often are complex, are not widely available, and do not reliably detect functional abnormalities.

Occasionally, diseases that are thought to be functional are ultimately found to be associated with abnormalities that can be seen by the naked eye or under the microscope. Then, the disease moves out of the functional category. An example of this would be Helicobacter pylori (H. pylori) infection of the stomach. Some patients with mild upper gastrointestinal symptoms who were thought to have abnormal function of the stomach or intestines have been found to have stomachs infected with H. pylori. This infection can be diagnosed under a microscope by identifying the bacterium in biopsies from the stomach. When patients are treated with antibiotics, H. pylori and symptoms disappear. Thus, recognition of infections with Helicobacter pylori has removed some patients’ symptoms from the functional disease category.

The distinction between functional disease and non-functional disease may be blurry. Thus, even functional diseases probably have associated biochemical or molecular abnormalities that ultimately will be able to be measured. For example, functional diseases of the stomach and intestines may be shown ultimately to be associated with reduced or increased levels of normal chemicals within the gastrointestinal organs, the spinal cord, or the brain. Should a disease that is demonstrated to be due to a reduced or increased chemical still be considered a functional disease? In this theoretical situation, we can’t see the abnormality with the naked eye or the microscope, but we can measure it. If we can measure an associated or causative abnormality, should the disease no longer be considered functional, even though the disease (symptoms) are being caused by abnormal function? The answer is unclear.

Despite the shortcomings of the term functional, the concept of a functional abnormality is useful for approaching many of the symptoms originating from the muscular organs of the gastrointestinal tract. To repeat, this concept applies to those symptoms for which there are no associated abnormalities that can be seen with the naked eye or the microscope.

While dyspepsia is a major functional disease(s), it is important to mention several other functional diseases. A second major functional disease is irritable bowel syndrome or IBS. The symptoms of IBS are thought to originate primarily from the small intestine and/or colon. The symptoms of IBS include abdominal pain that is accompanied by alterations in bowel movements (defecation), primarily constipation or diarrhea. Indigestion and IBS may be overlapping diseases since up to half of patients with IBS also have symptoms of indigestion. A third distinct functional disorder is non-cardiac chest pain. This pain may mimic heart pain (angina), but it is unassociated with heart disease. Non-cardiac chest pain is thought to often result from a functional abnormality of the esophagus.

Functional disorders of the gastrointestinal tract often are categorized by the organ of involvement. Thus, there are functional disorders of the esophagus, stomach, small intestine, colon, and gallbladder. The amount of research that has been done on functional disorders is greatest in the esophagus and stomach (for example, non-cardiac chest pain, and indigestion), perhaps because these organs are easiest to reach and study. Research into functional disorders affecting the small intestine and colon (IBS) is more difficult to conduct, and there is less agreement among the research studies. This probably is a reflection of the complexity of the activities of the small intestine and colon and the difficulty in studying these activities. Functional diseases of the gallbladder (referred to as biliary dyskinesia), like those of the small intestine and colon, are more difficult to study, and at present, they are less well-defined. Each of the functional diseases is associated with its own set of characteristic symptoms.

• Small intestinal bacterial overgrowth (SIBO): A potential cause of indigestion is a bacterial overgrowth of the small intestine, although the frequency with which this condition causes indigestion has not been determined, and there is little research in the area. The relationship between overgrowth and indigestion needs to be pursued, however, since many of the symptoms of indigestion are also symptoms of bacterial overgrowth. Overgrowth can be diagnosed by hydrogen breath testing and is treated primarily with antibiotics.

Other diseases and conditions can aggravate indigestion and other functional diseases.

• Anxiety and/or depression: are probably the most commonly-recognized exacerbating factors for patients with functional diseases.
• The menstrual cycle: During their periods, women often note that their functional symptoms are worse. This corresponds to the time during which the female hormones, estrogen, and progesterone, are at their highest levels. Furthermore, it has been observed that treating women who have indigestion with leuprolide (Lupron), an injectable drug that shuts off the body’s production of estrogen and progesterone, is effective at reducing symptoms of indigestion in premenopausal women. These observations support the role of hormones in the intensification of fun.

  Non-gastrointestinal indigestion causes

  It’s not surprising that many gastrointestinal (GI) diseases have been associated with indigestion. However, many non-GI diseases also have been associated with indigestion. Examples of non-GI causes of indigestion include:

  • Diabetes
  • Thyroid disease
  • Hyperparathyroidism (overactive parathyroid glands)
  • Severe kidney disease

  It is not clear, however, how these non-GI diseases might cause indigestion.

  Another important cause of indigestion is drugs. Many drugs are frequently associated with indigestion, for example, nonsteroidal anti-inflammatory drugs (NSAIDs such as ibuprofen), antibiotics, and estrogens). Most drugs are reported to cause indigestion in at least some people with functional symptoms.

Symptoms of indigestion

We usually think of symptoms of indigestion as originating from the upper gastrointestinal tract, primarily the stomach and the first part of the small intestine. These symptoms include:

• Upper abdominal pain or discomfort (above or around the navel)
• Belching
• Nausea (with or without vomiting)
• Abdominal bloating (the sensation of abdominal fullness without visible distention)
• Early satiety (the sensation of fullness after a very small amount of food)
• Abdominal distention (visible swelling as opposed to bloating)
• Lower chest pain

Symptoms most often are provoked by eating, which is a time when many different gastrointestinal functions are called upon to work in concert. This tendency to occur after meals is what gave rise to the erroneous notion that indigestion might be caused by an abnormality in the digestion of food.

Increase in Symptoms of Indigestion

People of all ages and of both sexes could be affected by indigestion because of unhealthy lifestyle it’s extremely common nowadays.

Indigestion individual’s risk increases with :

• Alcohol consumption.
• Smoking.
• Use of allopathic drugs (they irritate the stomach).
• Conditions where there is an abnormality in the digestive tract, such as an ulcer
• Emotional problems (anxiety, depression).

Causes of Indigestion :

Indigestion has many causes for example :

• Ulcers (blood in vomit – the vomit may look like coffee grounds)
• GERD
• Stomach cancer (rare)
• Gastroparesis (a condition where the stomach doesn’t empty properly; this often occurs in people with diabetes)
• Stomach infections
• Irritable bowel syndrome
• Chronic pancreatitis
• Thyroid disease
• Pregnancy
• Allopathic medication.
• Eating too much, eating too fast, eating high-fat foods, or eating during stressful situations (included watching TV, Cell phone etc.)
• Drinking alcohol
• Smoking
• Stress and fatigue.
• Bad sleeping style.
• Too much coffee intake/tea toddlers.