What are the signs of hypochlorhydria, or low stomach acid?

Low stomach acid — also called hypochlorhydria — happens when your body doesn’t produce enough hydrochloric acid. 

Symptoms often appear soon after you eat. You might have abdominal pain or bloating, and you may notice changes to your bowel movements. 

Hydrochloric acid has a pH of around 2, which creates a very acidic environment in your stomach. If there’s not enough acidity, food might stay in your stomach or travel into your gut before it's digested properly.  

When this happens, the food can start fermenting, which can cause gas and bloating. It can also disrupt the balance of microbes in your gut.  

Without treatment, low stomach acid can lead to a vitamin or mineral deficiency. Luckily, with the right medical attention, treatment is often successful, and it’s possible to reverse the effects. 

Symptoms of low stomach acid 

Eight short-term symptoms of hypochlorhydria include:  

1. stomach pain 

2. heartburn 

3. nausea 

4. bloating 

5. diarrhea

6. feeling full sooner than usual 

7. acid regurgitation

8. constipation 

Long-term effects and complications 

Without treatment, hypochlorhydria can cause complications. These often stem from your stomach being unable to absorb nutrients properly.

Some complications include: 

• unexplained weight loss

• a vitamin B12 deficiency

• an iron deficiency 

• an overgrowth of bacteria in your small intestine, which is also called SIBO 

• an increased risk of bacterial infections

• gastric cancer

Causes and risk factors 

The most common causes of hypochlorhydria are: 

• Atrophic gastritis: This is a disease resulting from long-term inflammation of the stomach lining. It usually stems from an autoimmune disorder or an infection with Helicobacter pylori bacteria.  

• Medication for heartburn: Proton pump inhibitors, or PPIs, are drugs that reduce stomach acid. They can cause hypochlorhydria if you use them for a long time. 

Factors that might increase your risk of having low stomach acid include: 

• stomach surgery, such as gastric bypass surgery

• a lot of ongoing stress

What else could it be?   

Here are some other conditions that cause symptoms similar to those of low stomach acid: 

• High levels of stomach acid: Too much stomach acid can also cause abdominal discomfort, bloating, heartburn, and diarrhea. 

• Gastroesophageal reflux disease, or GERD: This involves stomach acid traveling up into the esophagus.

• Hiatal hernia: This occurs when the top part of the stomach pushes up through a gap in your diaphragm. 

• Stomach ulcer: The lining of your stomach becomes damaged, and a sore develops.

• Gastroparesis: The muscle movements of your stomach stop or slow, keeping your stomach from emptying as it normally would.

• Pregnancy: Due to hormonal changes, the digestive process slows, which can lead to acid reflux and heartburn.

• Stress and anxiety: Some of the physical symptoms can be similar to those of low stomach acid.

• Gallstones: These are small stones that form in your gallbladder. If one gets stuck in your gallbladder’s opening, it can cause abdominal pain.

• Heart disease: Pain in the center of the chest is also a symptom of cardiovascular disease. It can be hard to tell the difference between pain from this and from low stomach acid.

Some foods can also trigger reflux-type symptoms. The main culprits are fatty, spicy, and acidic foods. Eating large meals and eating quickly can also cause these symptoms. 

Tests and diagnosis 

If your doctor suspects low stomach acid, due to your symptoms and medical history, they might order a pH test of your stomach. 

A healthy level of stomach acid creates a pH between 1 and 2. A pH reading of over 3 might mean that your stomach isn’t producing enough acid.

If the level is over 5, there could be no acid, and the medical term for this is achlorhydria. 

If low acid seems likely, your doctor might order further tests — to check for vitamin or mineral deficiencies, for example — and they’ll refer you to a digestive specialist.

Can you test your stomach acid levels at home?

No, you can’t test your stomach acid levels at home.

On platforms such as TikTok, something called “the baking soda test” has become popular.  

The theory is that when you drink baking soda, it mixes with your stomach acid and starts a chemical reaction. This reaction produces carbon dioxide, which makes you burp.  

If it takes a long time for you to burp, this might mean there’s not enough acid in your stomach.   

Drinking baking soda can be harmful for some people. And in large doses, it can be poisonous. We don’t recommend that you try this test.

If you’re concerned about your symptoms, speak with a healthcare professional. 

Treatment options 

If your doctor finds the root cause of hypochlorhydria, they’ll address that first. It could mean:

• changing your current medication, if it's safe

• taking antibiotics for an H. pylori infection

• finding ways to reduce stress 

If there’s no obvious cause, they might suggest treatment with a hydrochloric acid supplement to directly reverse the low levels of acid.

If you have a vitamin or mineral deficiency, the doctor may also give you a supplement to increase your levels. 

Can you increase your stomach acid levels naturally? 

There’s currently no scientific evidence that you can significantly increase your stomach acid levels naturally.

Some internet articles suggest that apple cider vinegar might help reduce your stomach pH. The vinegar has a pH of between 2 and 3, so it might help. But, again, no scientific evidence supports this.  

Bile supplements and digestive enzymes are available, and manufacturers claim that these can help improve digestion generally.

Still, there’s no clear evidence that these supplements and enzymes increase stomach acid levels.

Diet and low stomach acid 

Having low levels of stomach acid unsettles the balance of microorganisms in your gut, allowing harmful bacteria the chance to grow there.

Different plants contain different prebiotics, which fuel different gut bugs. So, eating a range of plants encourages diversity in your gut microbiome. This diversity is linked to a better-functioning gut.

Probiotic foods might be helpful, too. They contain living microbes that can boost the number and diversity of “good” bacteria in your gut.

Probiotics can also support H. pylori treatment. In particular, research has shown that Lactobacillus strains are effective in children. 

When you have any digestive disorder, doctors often recommend easily digestible foods, like stews, soups, and slow-cooked meals.

Another way to support your digestion is to take small bites and chew thoroughly.

To learn more about how your eating rate can affect your health, listen to the ZOE Science & Nutrition podcast episode on the topic. 

Outlook 

Without treatment, low stomach acid can damage your stomach lining and lead to nutritional deficiencies. Getting treatment early can reduce the risk of these complications.  

Many causes of low stomach acid have quite simple treatments. It might just involve adjusting aspects of your diet and lifestyle, switching medications, or taking a supplement.

Summary

Hypochlorhydria is the medical name for low stomach acid.

It can cause a number of digestive issues, increase your risk of bacterial infections, and lead to more serious complications if you don’t get treatment.

Also, having a healthy diet with a variety of plants will support your gut microbiome and help keep levels of “bad” bacteria in check.

With the ZOE at-home test, you can find out which bacteria live in your gut and which foods support the “good” ones. You can learn how it works by taking our free quiz.