All the Things We Were Never Taught About Stomach Acid (and Why It Matters)

Without a doubt, one of the most common underlying “root causes” I see in my practice is low stomach acid, also known as hypochlorhydria. But even then, low stomach acid isn’t always the true root—it’s often a symptom of something deeper.

So what’s behind it for most people? Stress. And I’ll go ahead and throw in alcohol, too—because alcohol is technically a stressor on the body. Stomach acid also naturally declines with age, which I take into account with every client I work with.

The Domino Effect of Low Stomach Acid

When stomach acid is low, it doesn’t just affect digestion—it can impact your entire body. Some of the trickle-down symptoms I see include:

• Chronic cough
  
• Asthma symptoms
  
• Bloating
  
• Acne
  
• Fatigue
  
• Hormone imbalances
  
• Belching
  
• Acid reflux, heartburn, and even GERD
  
• Nausea
  
• Slow digestion or delayed stomach emptying
  
• Undigested food in the stool
  
• Leaky gut (aka intestinal permeability)
  
• Gas
  
• Food sensitivities
  
• SIBO
  
• Bacterial or parasitic overgrowths
  

Let’s pause and think about this:
Your stomach, next to your skin, is your first line of defense.

If your stomach acid isn’t strong enough, pathogens and improperly broken-down food pass right through the gates into your delicate GI tract. That’s where your immune system lives, where your neurotransmitters like serotonin and dopamine are made, and where inflammation can easily take hold.

What Is Stomach Acid Really Supposed to Do?

Your stomach acid (HCl, or hydrochloric acid) has a normal pH of around 0.8—incredibly acidic. For reference, water sits at a pH of 7. Even at rest, your stomach hovers between 1–3 on the pH scale. That acidity matters a lot.

Here’s a simple analogy I use:

Imagine your stomach has a trapdoor at the bottom, and the only way it opens is with a secret password. That password? Stomach acid.

If your acid isn’t strong enough to hit the right pH, that trapdoor doesn’t open. Your food just sits there—fermenting, creating gas, and pressurizing your stomach. Eventually, that pressure pushes upward, not downward.

That’s what most people feel as acid reflux. It’s not that you have too much acid… you likely have too little.

The Problem with Antacids & Acid Blockers

Now here’s where the cycle gets messy:

Pharmaceutical companies tell you to reach for TUMS or antacids when you feel that burn. But what they don’t tell you is that these products further reduce stomach acid, compounding the problem.

Long-term use leads to more imbalances, more nutrient deficiencies, and more confusion about what’s actually going on. It’s a classic case of treating the symptom instead of the root.

Why Does Stomach Acid Actually Matter?

So glad you asked. Here are the top reasons:

1. It breaks down your food—especially protein.

Stomach acid activates pepsin, an enzyme needed to break down protein into usable amino acids, and protein is one of the hardest things for our body to break down. So while I am a HUGE proponent of the Internet reminding us to increase our protein, we also want to make sure that we can properly break it down.

2. It helps you absorb key nutrients.

Without enough HCl, you’ll struggle to absorb vitamin B12, iron, calcium, magnesium, and zinc—all essential for energy, fertility, hormones, and immune health.

3. It kills harmful bacteria and pathogens.

HCl is your front-line immune defense in the digestive tract. Without it, bad bugs like H. pylori, parasites, and bacteria can move in and thrive.

4. It signals the rest of your digestive system.

Stomach acid tells your liver to release bile and your pancreas to secrete enzymes—both crucial for digesting fats and carbohydrates.

Why I Don’t Just Slap on a Supplement

In my practice, I don’t just throw a digestive supplement at the issue and move on. If someone has low iron or B12, I want to know: why isn’t their body absorbing it? Is the breakdown happening properly? Is the terrain even prepared to receive that supplement?

Supporting stomach acid is one of the few areas where you can use targeted support without creating dependency—unlike enzymes, which the pancreas can become reliant on when overused. Still, I always want to support the body and address the root cause.

So What Causes Low Stomach Acid?

Here are the most common root contributors:

1. Chronic Stress

Stress activates your sympathetic nervous system (fight or flight), which shuts down digestion. If you’re eating in a rushed, anxious, or distracted state, your body won’t produce enough acid to digest properly.

2. Aging

Stomach acid naturally declines with age—especially after 40. This often leads to nutrient deficiencies and sluggish digestion in older adults.

3. Poor Eating Habits

These habits can all suppress acid production:

• Eating on the go
  
• Not chewing properly
  
• Drinking large amounts of water with meals
  
• Eating ultra-processed foods

4. Long-Term Use of Antacids or PPIs

Medications like TUMS, Nexium, and Prilosec reduce stomach acid in the short term but can lead to chronic low acid and nutrient malabsorption when overused.

5. Nutrient Deficiencies

Your body needs certain nutrients to make stomach acid—especially:

• Zinc
• Vitamin B1 and B6
• Chloride
  Deficiencies here slow down HCl production.
• Sodium

6. Infections Like H. pylori

This sneaky bacterium is a common root cause of low stomach acid and often goes undetected on standard tests. It damages the stomach lining and suppresses acid production, leading to bloating, reflux, and more.

7. Alcohol, Smoking & Certain Medications

These irritate the stomach lining and impair the parietal cells that produce HCl.

8. Hypothyroidism & Metabolic Imbalances

Low thyroid function can slow everything down—including stomach acid production. Blood sugar issues and adrenal dysfunction can also throw off your digestive function.

 Final Thoughts

If no one’s ever talked to you about the importance of stomach acid before—welcome to the truth that could change your health journey.

Stomach acid isn’t just about digestion—it affects your skin, energy, immunity, hormones, and mental health. It’s one of the very first things I assess and support with clients, and I’ve seen firsthand how powerful it is to restore this essential piece of the puzzle.

Has anyone you’ve worked with before ever considered your stomach acid levels?

If not—now’s a great time to start.

Warmly,
Ashley