12 Root Causes of Low Stomach Acid (And How to Fix It)
If you’re dealing with bloating, acid reflux, or that heavy, uncomfortable feeling after meals… there’s a good chance low stomach acid is part of the problem.
Even though it’s rarely talked about by conventional doctors, low stomach acid (also called hypochlorhydria) is a massive roadblock to digestion, gut health, and overall well-being. And here’s the kicker—it doesn’t just happen out of nowhere.
In this post, we’re diving into the 12 most common root causes of low stomach acid, so you can stop guessing and start healing.
Why Stomach Acid Even Matters
Stomach acid (aka hydrochloric acid or HCl) isn’t just there to cause heartburn—quite the opposite. It’s actually your first line of defense for proper digestion. It helps break down proteins, absorb nutrients like B12, magnesium, and iron, and keeps unwanted bacteria and pathogens from overgrowing in the gut.
So when your levels are too low, things go south quickly:
→ Bloating after meals
→ Undigested food in your stool
→ Nutrient deficiencies
→ Increased risk of SIBO and leaky gut
→ Chronic fatigue or brain fog
Sound familiar?
Let’s explore what might be shutting off that critical acid production.
12 Root Causes of Low Stomach Acid
1. Poor Eating Hygiene
How you eat matters just as much as what you eat. Scarfing down meals, multitasking while eating, or drinking too much liquid with food signals your nervous system to stay in “fight or flight” instead of “rest and digest.” That means your body doesn’t prioritize stomach acid production.
2. Chronic Stress
Stress shuts down digestion. It diverts your body’s resources away from breaking down food and into survival mode. Over time, chronic stress blunts stomach acid output, which makes digestion harder and keeps you locked in the gut-stress feedback loop.
3. Proton-Pump Inhibitors (PPIs)
PPIs like omeprazole and pantoprazole are designed to block acid production. And while they can be helpful short term for acid reflux, long-term use leads to suppressed acid output even after you stop taking them.
4. H2 Receptor Blockers
Drugs like Pepcid (famotidine) and Zantac (ranitidine) reduce stomach acid by blocking histamine—a necessary component in acid production. Regular use can quietly interfere with digestion and nutrient absorption.
5. Antacids
While these give temporary relief, they neutralize acid your stomach needs to break down food. Used regularly, they reduce the overall effectiveness of your digestion and make symptoms worse over time.
6. H. pylori Infection
Helicobacter pylori is a bacteria that damages stomach lining and acid-producing cells. It raises stomach pH and causes ulcers—but even before that happens, it may silently suppress acid production. You can test for it via stool or breath testing.
7. Hypothyroidism
Thyroid hormones regulate your metabolism—including digestion. When your thyroid is underactive, your stomach slows down too. That means reduced acid production and sluggish motility, which can lead to bloating, constipation, and nutrient deficiencies.
8. Vitamin & Mineral Deficiencies
Your body needs nutrients like zinc, iron, magnesium, and B12 to make stomach acid. But guess what? You also need stomach acid to absorb these same nutrients. It’s a vicious cycle, especially if your diet is lacking or your digestion is impaired.
9. Hypoadrenal State (Low Cortisol)
Low-functioning adrenal glands (sometimes called adrenal fatigue) lead to poor energy regulation and decreased stomach acid production. This often shows up as fatigue, dizziness, and poor appetite—all signs your digestion is compromised.
10. Chronic NSAID Use
Pain relievers like ibuprofen and naproxen can erode your stomach lining over time. They weaken the mucus barrier and damage the parietal cells responsible for producing acid, making it harder to digest food and increasing the risk of ulcers.
11. Autoimmune Atrophic Gastritis
In some autoimmune conditions, your body starts attacking its own stomach lining or the intrinsic factor needed to absorb B12. This leads to long-term damage and severely reduced acid production. Conditions like pernicious anemia fall under this umbrella.
12. Aging
By the time we hit 60, up to 30% of us may have significantly reduced stomach acid levels. This makes it harder to absorb key nutrients like protein, calcium, and iron—key factors in healthy aging.
What You Can Do About It
The good news? Low stomach acid can be corrected—once you identify the root cause. Here’s what I recommend as a gut health expert and licensed pharmacist:
✅ 1. Identify and fix your root cause
If you're on acid blockers, have nutrient deficiencies, or struggle with chronic stress or thyroid issues—start there. That’s your foundation.
✅ 2. Fix your eating hygiene
How you eat matters. Slow down, chew thoroughly, avoid multitasking, and sip water instead of chugging it during meals.
✅ 3. Support acid production with betaine HCl or ACV
In some cases, gentle acid support can help retrain your stomach and restore proper digestion. Use these supplements in the middle of meals for best results, and always remember to start with the lowest possible dosage, and increase slowly as needed.
The Bottom Line
Low stomach acid is more than just a digestion issue—it affects how you feel, think, and absorb nutrients every single day.
It’s one of the most overlooked issues I see in people with bloating, SIBO, and chronic gut symptoms. But once you identify the root cause, the path forward becomes much clearer.
And if you're looking for a supplement to support your gut lining while you do this deeper work, check out Bloat Blocker—my patent-pending formula created specifically for people with IBS and SIBO.
Let’s get you back to feeling good after meals again.