Hypochlorhydria is a deficiency of stomach acid. If you don’t have enough stomach acid, you can’t digest food properly or absorb its nutrients. This leads to indigestion, malnutrition and sometimes bacterial overgrowth. Fortunately, hypochlorhydria is relatively simple to test and treat.


What is hypochlorhydria?

Hypochlorhydria means low stomach acid — specifically, low hydrochloric acid (HCI), which is the most powerful acid your stomach produces. Hydrochloric acid plays an important role in your digestion and immunity. It helps break down protein and absorb essential nutrients, and it helps control viruses and bacteria that might otherwise infect your stomach.

If you have hypochlorhydria, you’ll have trouble digesting food properly, especially protein. Over time you can develop serious nutritional deficiencies. You’ll also be prone to infections, which can cause further damage to your stomach and digestive system.


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What is the difference between hypochlorhydria and hyperchlorhydria?

“Hypo-” means “low.” “Hyper-” means “high.” Hypochlorhydria means your stomach isn’t producing enough hydrochloric acid. Hyperchlorhydria means it produces too much. In the U.S., people most often attribute their digestive problems to hyperchlorhydria, and they often use medication to suppress their stomach acid. But in fact, symptoms of chronic acid reflux, laryngopharyngeal reflux or heartburn can also be caused by hypochlorhydria. Poor digestion from the lack of stomach acid can create gas bubbles that rise into your esophagus and throat, carrying stomach acid with them. Even trace amounts of acid in your throat can feel like too much.

How does hypochlorhydria affect my body?

Stomach acid is necessary for digestion and absorption of protein, vitamin B12 and several minerals. When your body is no longer able to break down and absorb these nutrients, you end up with undigested food and nutritional deficiencies. Protein and vitamin B12 deficiencies lead to iron deficiency anemia as well as vitamin deficiency anemia, which affects your nervous system. Calcium and magnesium deficiencies lead to osteoporosis.

Undigested food in your GI tract causes a range of uncomfortable GI symptoms in the short term and leads to more serious problems in the long term. For example, undigested food left to ferment in your GI tract can lead to gut bacteria overgrowth in your small intestine (SIBO). Low stomach acid also leaves you vulnerable to overgrowth of other common bacteria, including H. pylori, which is associated with chronic gastritis and peptic ulcer disease.


Symptoms and Causes

What causes hypochlorhydria?

The most significant causes include:

  • Atrophic gastritis. The most common cause is a condition called atrophic gastritis, which is when the cells that secrete stomach juices atrophy and stop working. Atrophic gastritis is the end result of chronic inflammation of the stomach (gastritis). Chronic gastritis can be caused by a variety of things, including bacterial infection (H. Pylori), alcoholism and autoimmune disease.
  • H. pylori infection. This common bacterial infection affects about half of us in the U.S. In some people, H. pylori causes no symptoms, but in others, it can take over, fighting and eventually decreasing stomach acid. Ironically, low stomach acid can also allow for H. pylori to take over.
  • Acid-reducing medications. Chronic use of antacids, H2 receptor blockers, and especially proton pump inhibitors (PPIs) can cause low stomach acid. PPIs were originally approved only for short-term use, but they are now commonly overprescribed and used to treat chronic symptoms such as GERD and heartburn. Eventually, they can cause the acid-secreting glands in the stomach to stop working.

What are the symptoms of hypochlorhydria?

Immediate symptoms involve indigestion, including:

  • Abdominal pain.
  • Bloating.
  • Gas.
  • Diarrhea.
  • Constipation.
  • Undigested food in poop.
  • Reflux.
  • Heartburn.

Prolonged hypochlorhydria may produce symptoms of nutritional deficiencies, including:

  • Brittle fingernails.
  • Hair loss.
  • Paleness.
  • Fatigue.
  • Weakness.
  • Numbness or tingling in hands and feet.
  • Memory loss.
  • Headaches.

Other contributing causes may include:

  • Advanced age. Cells age as we do, and over time, the cells that produce stomach acid can begin to die off.
  • Chronic stress. This doesn’t mean common, everyday stress. But if you have significant stress sustained over a long period of time, it can affect your stomach acid production.
  • Stomach surgery, including gastric bypass surgery, is known to affect stomach acid production.


What risk factors are associated with hypochlorhydria?

  • Being over the age of 65.
  • Prolonged use of antacids or PPIs.
  • H. pylori infection.
  • History of gastritis or stomach ulcers.
  • History of stomach surgery.

Diagnosis and Tests

How can I tell if I have low stomach acid?

The symptoms of hypochlorhydria — symptoms of indigestion, nutritional deficiencies and possibly bacterial infection — can be caused by many things. Hypochlorhydria is only one possible cause. If you have several of the risk factors associated with low stomach acid, you might suspect that is your problem. But there’s no way to know for sure without taking a stomach acid test.

Healthcare providers use a variety of tests to diagnose hypochlorhydria. There are also some DIY tests you can try at home. These may not be as accurate, but they offer a relatively simple and inexpensive way of exploring your theory. We recommend that if you do get a positive result from an at-home test, you follow up with a trained healthcare provider.

The baking soda test

The theory behind this at-home is that baking soda combined with stomach acid produces carbon dioxide (C02), which will cause you to burp. For the test, you’ll drink half a glass (4 ounces) of cold water combined with a quarter teaspoon of baking soda, on an empty stomach. Then time how long it takes you to burp. If it takes longer than three to five minutes, the theory goes, you don’t have enough stomach acid.

How is hypochlorhydria diagnosed?

Your healthcare provider will conduct a physical exam and listen to your symptoms and health history. If they suspect hypochlorhydria, they will suggest one of several stomach acid tests.

Medical tests to diagnose stomach acid include:

  • The Heidelberg pH test. For this test, you’ll swallow a small capsule with a radio transmitter that measures the pH levels in your stomach. After taking a baseline measurement, you’ll drink a baking soda solution to neutralize your stomach acid. Then the test measures how long it takes your stomach to return to baseline acid levels. This tells healthcare providers how well your stomach produces and secretes acid.
  • The SmartPill test. The SmartPill is another wireless transmitter that you swallow. Unlike the Heidelberg test, which measures pH levels, the SmartPill measures gastric acid levels.
  • The gastric string test. This test involves swallowing a capsule attached to a string, then pulling it out by the string after 10 minutes. The string is tested with pH paper. Normal stomach acid has a pH level of one to two, which is highly acidic, with zero being the most acidic level on the scale. If you have hypochlorhydria, your stomach acid might be more in the range of three to five. Above five is a severe condition called achlorhydria, which means you have virtually no hydrochloric acid.

If you test positive for hypochlorhydria, your healthcare provider may want to follow up with additional tests to detect nutritional deficiencies or bacterial infections. They’ll use all of this information to design your treatment plan.

Management and Treatment

How is hypochlorhydria treated?

Treating hypochlorhydria is a three-pronged process.

  • Address underlying causes. If your healthcare provider has been able to identify the cause of your hypochlorhydria, the first step will be to address that. This might mean adjusting your medication prescriptions, treating an underlying health condition, or fighting a bacterial infection with antibiotics.
  • Supplement hydrochloric acid. To treat the hydrochloric acid deficiency itself, your healthcare provider may prescribe an HCI supplement (betaine hydrochloride) to take with meals. HCI supplements are often combined with the enzyme pepsin. These supplements can help your digestion. Sometimes, they help your stomach acid gradually return to normal levels, and you can discontinue taking them. They are available over the counter, but they are not for everyone, so you should talk to your healthcare provider first before self-prescribing.
  • Supplement nutritional deficiencies. If your low stomach acid caused other deficiencies, such as iron, calcium or vitamin B12, your healthcare provider may recommend supplements to help replace those nutrients.

Outlook / Prognosis

What is the prognosis for hypochlorhydria?

This condition can often be reversed, or at least successfully treated, with HCI supplements. It’s important to address the underlying causes, however. If you have an infection, disorder or inflammatory condition, these will continue to cause problems, including hypochlorhydria and others. Make sure to get a thorough medical screening before treating with HCI supplements. Your healthcare provider can help ensure you’re treating the causes and effects of hypochlorhydria, including specific nutritional deficiencies.

Living With

What’s a good diet for low stomach acid?

Diet alone won’t restore your stomach acid, but these guidelines may help improve your digestion while living with hypochlorhydria:

  • Eat protein first. Protein at the beginning of your meal helps to stimulate acid production.
  • Drink fluids later. Save drinks until at least 30 minutes after you’ve finished your meal. This gives your stomach more time to produce acid and metabolize proteins.
  • Eat probiotic foods, including yogurt, miso and sauerkraut, to help boost your good gut bacteria and keep harmful bacteria in check.
  • Avoid overly fatty and processed foods, which are harder to digest and offer little nutrition.
  • Fortify your vegetarian diet. Many of the deficiencies associated with low stomach acid, including protein, iron, calcium and vitamin B12, are most abundant in animal-sourced foods, such as meat, fish and dairy products. If you’re a vegetarian, make sure you’re supplementing these nutrients. This might be easiest with a quality health shake blend.
  • Eat smaller meals and chew thoroughly to give your digestive system its best chance to break the food down.
  • Finish your last meal two to three hours before bedtime. Give your body time to digest before lying down.

A note from Cleveland Clinic

Hypochlorhydria, or low stomach acid, is a relatively underdiagnosed condition that may be more common than we know. Symptoms commonly associated with hyperchlorhydria, or high stomach acid, including heartburn and reflux, may actually stem from hypochlorhydria. Medications to treat high stomach acid can contribute to low stomach acid, making digestive problems worse. Successful treatment requires careful diagnosis and testing. Medical tests can identify high or low stomach acid as well as other important factors that may be contributing to your symptoms. With the right information, your healthcare provider can help you make a plan to treat the causes and effects of hypochlorhydria.

Medically Reviewed

Last reviewed on 06/27/2022.

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