What is the pH of gastric acid

Additional information

Definition - What is the normal pH level in the stomach?

The stomach contains the so-called Gastric juice, a clear, acidic liquid. This contains dilute hydrochloric acid in large amounts.

The pH value of the gastric juice is sober, i.e. without any foodbetween 1.0 and 1.5. If the stomach is filled with porridge, increases the pH in the stomach to values between 2 and 4. On an empty stomach or filled with food, the pH value in the stomach remains in the acidic area.

What is the pH of the stomach acid?

Stomach acid is an aqueous solution that contains hydrochloric acid. The acid is necessary to the Chyme in the stomach too disassembleso that it can be further processed in the intestine. The term Gastric juice describes the complete mixture, that all Enzymes, so-called Mucin, Bicarbonate, hydrochloric acid, water etc. contains, i.e. all substances that are produced in the stomach.

Since gastric juice consists to a large extent of gastric acid and water, the terms gastric juice and gastric acid are mostly used synonymously (synonymously). Due to the high hydrochloric acid content, the pH value of the stomach acid is in the acidic range 1 to 1.5. When you eat and your stomach goes with it Chyme fills, the pH rises to values between 2 and 4. The pH value of the stomach acid usually always remains in the acidic range.

When the gastric glands too much or too little stomach acid can form, the PH value in the stomach change. The balance between decomposition of food and protection of the stomach wall cells can change. Symptoms of over-acidification can occur, such as inflammation of the gastric mucosa (Gastritis),an ulcer or Reflux (Heartburn). If there is a lack of stomach acid, digestive disorders or frequent infections can occur.

What increases the pH?

A lack of stomach acid can have a number of reasons. Takes the Stomach acid in the stomach from, increases the PH value on, so the naturally acidic pH becomes less acidic. Incorrect / too frequent use of anti-gastric drugs obviously leads to a decrease in acidity in the stomach and thus to an increased pH value. Examples are the proton pump inhibitors omeprazole and pantoprazole. For optimal effect, the medication must be used after the doctor recommended dose.

A chronic inflammation of the stomach lining (gastritisType A) can also lead to an increase in pH. The formation of acid in the stomach is greatly reduced. In addition, a Anemiathrough a Vitamin B12 deficiency conditionally affect gastric acid production also negatively. One speaks of one pernicious anemia. This can also be done by a Inflammation of the stomach lining caused. Not infrequently, the disease is one Autoimmune disease which destroys the stomach acid-producing cells in the stomach. As this results in less stomach acid, the pH value in the stomach rises.

Test stomach cramps with diarrhea

Do you suffer from stomach cramps with diarrhea and would you like to know what could be the cause of your symptoms? Take part in our self-test and answer the following10 quick questions. Click here to go directly to the Test stomach cramps with diarrhea

What lowers the pH?

The pH is too low, though too much acid is available. A Overacidification of the stomach (hyperacidity) can arise when the parietal cells in the gastric glands produce too much stomach acid. Increased gastric acid production lowers the pH value.

A unhealthy diet, caffeine, Smoke and stress also lead to over-acidification of the stomach, so that the pH value decreases. The caffeine from coffee and nicotine from cigarettes stimulate the stomach wall cells to produce more acid. This decreases the pH in the stomach. In addition, it is often said that “The stress makes me feel bad”. It is said that stress can cramp up the stomach. In this way, the production of stomach acid is stimulated. The stomach acid increases, the pH value in the stomach decreases and complaints likeheartburn occur. There can also be a colonization of the stomach lining with the bacteriumHelicobacter pylori lead to increased acid formation in the stomach. Infection with this bacterium often causes inflammation of the stomach lining and increases the risk of developing one Ulcer in the stomach.

What are the long-term consequences of an acidic stomach?

If the stomach is briefly overly acidic, this usually does not cause any complaints or consequences. However, if there is increased gastric acid production over a long period of time, the Mucous membrane of the stomach and duodenum. The damage to the stomach lining can cause symptoms such as acidic Eructation, heartburn, stomach pain, nausea, Vomit or Loss of appetite.

A acute gastric mucosal inflammation (gastritis) or a ulcer can be behind it. At aStomach ulcer(Gastric ulcer) the mucous membrane is damaged in one place. Often, excessive gastric acid production is responsible for the development of an ulcer. An ulcer occurs when the cell protection of the gastric mucosa and the gastric acid are no longer in balance. If the mucous membrane is not sufficiently protected from the acid or if there is simply too much acid in the stomach, the gastric mucosa can become diseased and develop an ulcer.

Long term consequences like Inflammation of the gastric mucosa and stomach ulcers can often be prevented with a healthy lifestyle (balanced diet, if possible avoiding nicotine and alcohol). For other malfunctions or Helicobacter pylori Due to inflammation of the gastric mucosa, drugs such as proton pump inhibitors can be indicated and relieve symptoms and prevent worse.

You may also be interested in this topic:Symptoms of a stomach ulcer

How can you measure the pH in the stomach?

A Gastric juice examination, also Gastric secretion analysis called, examines the PH value and the Composition of gastric juice. A changed pH value can provide information about various diseases. When examining gastric juice, the pH sober and the attending physician uses one Nasogastric tube. This is a soft plastic tube that the doctor inserts through the nose or mouth and into the stomach after numbing the nasopharynx with a lubricant. The doctor sucks in some gastric juice through the tube, which is then examined in the laboratory. There the pH value of the gastric juice is measured.

The pH value in the stomach can also be measured indirectly with a 24 hour pH metry measure up. This is a long-term acid measurement in the section of the esophagus near the stomach. This examination method is often used in gastrointestinal medicine to Reflux symptoms, like for example heartburn, in which acidic stomach contents get back into the esophagus, to investigate.

Both examination methods can prove the acidity of the gastric juice. The gastric juice examination is an examination of the gastric juice in which the pH value of the gastric juice is measured directly. With 24-hour pH-metry, a backflow of gastric juice into the esophagus can be detected. The pH value of the gastric juice is measured.

What are proton pump inhibitors?

Protonon pump inhibitors (PPIs), too Proton pump inhibitors are currently the most effective Medication, to the Gastric acid build-up to reduce. The proton pump inhibitors reduce the release of gastric acid from the cells of the stomach wall. The formation and release of the acid takes place through the so-called Parietal cells the lining of the stomach. An enzyme (more precisely: the H.+/ K+-ATPase) pumps Protons (Protons are electrically positively charged particles, here the hydrogen particles are “H+“Meant) from the parietal cells. The protons are essential for the acidic properties of stomach acid. The more protons there are, the more acidic the stomach acid is.

Proton pump inhibitors work by interfering with this mechanism. The drugs reach the parietal cells and via the bloodstream inhibit the "proton pump". This blockage is permanent, which is why the acid-reducing effects of the drugs can last up to three days.


Omeprazole is an active pharmaceutical ingredient that is used for the prevention and treatment of gastric and duodenal ulcers.
It belongs to the group of drugs called proton pump inhibitors (PPIs). Often ulcers of the stomach or duodenum are caused by colonization of the bacterium Helicobacter pylori conditionally. To eradicate the germs, omeprazole is often given together with antibiotics. Omeprazole helps reduce stomach acid.


At Pantoprazole is it a Proton pump inhibitorswhich is used to reduce stomach acid.
Pantoprazole is often used for heartburn and inflammation of the esophagus, but also for stomach and duodenal ulcers. The medicine also comes from the bacteriumHelicobacter pylori related ulcers, reflux disease and the Zollinger-Ellison Syndrome (hormone-producing cancer of the pancreas) in question.

What is Helicobacter pylori?

Helicobacter pylori is Rod bacteriathat colonize the human stomach and one Inflammation of the stomach lining can cause. The bacterium gets by with little oxygen and is very common in developing countries. Worldwide, Helicobacter pylori infection occurs in 50% of the population.

These bacteria are absorbed through the mouth and thus reach the stomach, where they colonize the mucous membrane and multiply. The bacteria have optimal living conditions in the gastric mucosa, as the mucous membrane protects the germs from the aggressive gastric acid. The germs give off ammonia and live in an ammonia cloud, which also protects them from stomach acid. A acute infection caused with the bacteria Vomit and nausea. There can also be complaints such as heartburn, Eructation and Flatulence occur.

A chronic infection however, runs in many cases symptom-free. When complaints arise, they are common heartburn, Pressure in the stomach after eating, sour Eructation or Flatulence. With a chronic Helicobacter pylori Infection can eventually lead to a (peptic) gastric ulcer. The bacteria rarely promote the development of gastric cancer and a lymph gland cancer that occurs in the stomach, the MALT lymphoma. A Helicobacter pylori infection can be treated with various drugs. Mostly a "triple therapy" with two different antibiotics and a proton pump inhibitor is carried out over a week. In severe cases, a quadruple therapy with a third antibiotic is used.

Learn more about the bacterium: Helicobacter pylori


Quality assurance by: Dr. Nicolas Gumpert | Last change: 05.05.2021