stomach acid (hypochlorhydria)

Low Stomach Acid - Treatment, Causes and Symptoms

Stomach acid, which is primarily made up of hydrochloric acid (HCl), is produced by the stomach lining. It helps us to digest and absorb proteins and other nutrients in our diet. HCl also protects us by killing various pathogenic micro-organisms like parasites, yeast, and bad bacteria. As such, hydrochloric acid plays a vital role in our digestion.  But if levels are too low (hypochlorhydria) then the whole digestive process does not work properly increasing the  risk of food intolerance or food allergy. [Ref]

For the stomach to produce HCl, the body needs to absorb zinc from our diet. Zinc-rich foods include: pumpkin seeds, oysters and crab, beef and pork, fortified breakfast cereals, baked beans and cashew nuts. [More detail on zinc rich foods]

Low levels of stomach acid can result in deficiencies, such as a lack of iron, vitamin B-12, and calcium, and causes many digestive problems. Heartburn, sour stomach, or stomach upsets, nausea, and pain are often associated with excess acid but in fact low stomach acid can also causes these issues. What’s more research shows that far more people suffer from low stomach acid than from excess acid.

Proper stomach acid production is vital to unlocking perfect digestion. The digestive process downstream from the stomach is controlled chiefly by acid (pH) changes. If the pH is wrong from the beginning, everything downstream from the small intestine to the large intestine will likely be compromised. [Ref]



Low stomach acid is a trigger for poor digestive activity. Because food and nutrients can’t be broken down, they sit in the stomach and cause bacteria to build up. The main symptoms from this process are gas and bloating after eating. Other symptoms include:

  • Cramping
  • Nausea
  • Constipation
  • Heartburn or acid reflux
  • Halitosis (bad breath)
  • Loss of appetite for meat
  • Malodorous perspiration
  • Gastric reactivity to vitamin supplements
  • Sense of fullness after meals
  • Desire to avoid breakfast
  • Post meal sleepiness
  • Easily broken finger nails
  • Anaemia unresponsive to iron
  • Stomach cramps/pains
  • Chronic diarrhoea shortly after meals
  • Black or tarry stools
  • Undigested food in stools
  • Veganism
  • Long-term use of pharmaceuticals , particularly PPIs (Proton Pump Inhibitors) such as Omeprazole
Transparent icon of HCI

Causes of low stomach acid

Low stomach acid has numerous contributing factors, so it’s difficult to determine the exact cause of symptoms. Two common triggers are high stress levels and eating an unhealthy diet. Other factors include eating meals too quickly and consuming too much sugar. Also undiagnosed food sensitivities or allergies, as well as chronic illness, interactions from prescription drugs are well known causes. Old age increases the chance of some of these causes and therefore affects gastric acid production.

Stomach acid production can also be inhibited by stress, eating too many processed carbs, nutrient deficiencies, allergies, and/or excess alcohol consumption. Very low levels can lead to many health problems. Without adequate HCl, your body cannot properly defend against pathogenic microorganisms. Foods do not get fully broken down (which can actually cause acid reflux), and partially digested food stays in the stomach longer than it should. This causes food to ferment, putrefy, and become rancid, which can cause a host of symptoms and health problems.

The older you are, the more likely you are to have low acid levels. At least 30% of the population over the age of 65 have hypochlorhydria. [Ref] Stress and age contribute to low acid levels, as do nutrient deficiencies, including low levels of the mineral zinc and vitamins B1 and B6. Deficiencies in zinc and B vitamins are extremely common due to:

  • Lack of intake from food
  • Chronic stress
  • Depletion from drinking alcohol and/or smoking

Treatment for low stomach acid

We generally recommend taking supplements or increasing dietary intake of key nutrients, to start the process of regaining a regular level of stomach acid. Other elements in our programme may include:

  1. Guidance on chewing your food and take smaller bites to stimulate your digestive enzymes
  2. A balanced diet rich in fruits and vegetables can also increase your stomach acid levels
  3. Fermented vegetables such as kimchi and sauerkraut can naturally improve your stomach acid levels.
  4. Advice on drinking raw apple cider vinegar. As a fermented liquid it’s rich in substances that can help stimulate the break down bacteria in food.
  5. Input on eating ginger which is widely known for its anti-inflammatory properties and for reducing inflammation from low stomach acid.
Zinc spelt oout in wood, with raw food ingredients
photo of jars of 5 types of vegetables
high resolution image representing stomach acid

Tests and supplements

The Heidelberg Stomach Acid Test for hypochlorhydria involves a small capsule with a radio transmitter being ingested via a drink. This capsule measures the pH of the stomach. The drink helps as the solution includes baking soda which reduces acidity. So the baking soda will neutralise the HCl in the stomach. If the body does not return it to normal, it’s a sign of hypochlorhydria. 

A simpler baking soda stomach acid test can be conducted as a free at-home test. Clearly this is not as accurate as the Heidelberg test but gives a good indication of your stomach acid levels.

When you have stomach pain take a tablespoon of lemon juice. If the pain leaves, you may have low stomach acid. However should it make your symptoms worse, then you may have too much acid. Conversely if you crave sour foods, or grapefruit juice sits well on your stomach, then you may have too little HCl.