Type 1 Diabetes + Autoimmune Gastritis

Type 1 diabetes (T1D) usually doesn’t travel alone because it’s an autoimmune condition. Once your immune system decides to attack one part of your body, it (frustratingly) sometimes goes after other parts. One example that doesn’t get talked about nearly enough is autoimmune gastritis, a condition where the immune system quietly attacks the lining of your stomach.

Autoimmune gastritis is more common in people with T1D than most people realize, and it can sneak up on you because the early signs look like a lot of other common day-to-day health challenges like feeling tired, foggy or even a little off. This guide walks through what autoimmune gastritis is, why it happens, how healthcare providers (HCPs) catch it and what you can do to manage it if you’re diagnosed.

What is autoimmune gastritis?

Autoimmune gastritis, sometimes called type A gastritis, is a long-term condition where your immune system targets healthy cells in your stomach lining instead of, you know, actual threats. The National Institute of Diabetes and Digestive and Kidney Diseases’ (NIDDK) overview of gastritis and gastropathy is a good introduction if you want a quick explanation of the differences. According to NIDDK, gastritis means the lining is inflamed, while gastropathy means it’s damaged without much inflammation.

People with T1D are three to five times more likely to develop autoimmune gastritis than people without diabetes, and somewhere between 5 and 10% of people with T1D have it. It shows up more often in older adults and in women. And it rarely travels alone either—it’s linked to other autoimmune conditions, autoimmune thyroid disease being one of the more common companions.

How autoimmune gastritis develops

When your body is developing autoimmune gastritis, the immune system attacks cells called parietal cells, which live in your stomach lining and do two jobs: 

1. Make stomach acid
2. Produce a protein called intrinsic factor that helps your body absorb vitamin B12

When those cells are damaged, both jobs suffer. Your stomach makes less acid, and your body struggles to absorb B12 and iron. Left unchecked, that can eventually lead to iron-deficiency anemia, vitamin B12 deficiency or a specific type of anemia called pernicious anemia.

Signs and symptoms of autoimmune gastritis

Autoimmune gastritis is sneaky at first—often no symptoms at all. Most of what you’d actually notice comes later, once anemia and low B12 set in.

Watch for symptoms like:

• Pain in the upper belly
• Weakness or tiredness
• Trouble concentrating
• Shortness of breath
• Leg cramps
• Headaches
• A fast or pounding heartbeat
• Trouble sleeping
• Pale skin

None of these symptoms exactly scream “stomach problem,” which is exactly why autoimmune gastritis so often gets missed or blamed on something else—stress, being busy, diabetes burnout, whatever’s convenient. It doesn’t mean your HCP is bad or lazy. It’s good they often look for simpler answers first before jumping to a harsh conclusion like another autoimmune condition that no one wants! 

If low B12 goes untreated for a long stretch, it can start to damage your nerves too. So if signs recur and don’t improve, it may be worth exploring to at least rule it out before your body undergoes further damage. Getting this checked and treated will make you feel better. 

Signs of low B12 levels include:

• Numbness or tingling in your hands or feet
• Stiff or weak muscles
• Serious memory and thinking problems, sometimes described as dementia

That last one is rare, but it’s real, and it’s reversible if caught early. That’s one more reason not to brush off new symptoms that linger! 

Getting a diagnosis

Diagnosing autoimmune gastritis usually takes a combination of tests, not just one. 

To test for and diagnose autoimmune gastritis, your HCP may:

• Order blood tests to check your iron and vitamin B12 levels
• Test your blood for antibodies that target stomach cells or block B12 absorption
• Check your gastrin level, a hormone that rises when your stomach makes less acid
• Do an upper endoscopy, a procedure where a thin camera gets a look inside your stomach
• Take a small tissue sample, called a biopsy, during that endoscopy to check for damage

None of this happens in a single afternoon. It’s a process, and that’s normal.

Autoimmune gastritis treatment and monitoring

No treatment stops the immune system from attacking your stomach. That part isn’t reversible, at least not yet. But HCPs can absolutely treat what it causes. Low B12? Shots or high-dose B12 pills. Low iron? Supplements or IV iron. Straightforward, if not exactly fun.

What’s important to remember is that autoimmune gastritis also raises your risk of stomach cancer and a rarer growth called a gastric neuroendocrine tumor. That’s why HCPs often recommend regular endoscopies to keep an eye on things. How often you should get checked depends on your individual circumstances and your doctor’s advice.

We know the idea of having an increased risk of cancer is scary, but don’t let it infiltrate your day-to-day life. Just be aware and mindful, especially at regular checkups and if you notice any new health symptoms. 

If a growth turns up during one of your exams, your doctor will watch it closely. Some growths are removed, others aren’t. Your HCP will make that judgment and recommendation.

What you can do if you believe you may have autoimmune gastritis

A few things worth bringing up at your next appointment, especially if you’ve had T1D for a while or already have another autoimmune condition and believe you may have autoimmune gastritis include:

• Ask if it makes sense to check your B12 and iron levels: this is particularly important if you’ve been feeling unusually tired or foggy. Only you know your baseline energy level. If it feels low, trust your gut and speak up with your healthcare team.
  
• Mention any family history of autoimmune conditions: it’s relevant context your doctor may not otherwise have. Don’t assume they already have all the information they need on file.
  
• If you’re diagnosed, ask how often you’ll need endoscopic monitoring going forward: write it down somewhere you’ll actually see it again or create a calendar reminder.

None of this requires you to become your own doctor. It just means showing up to appointments with better questions.

When to seek care right away

Most of this moves slowly, so there’s rarely a reason to panic. 

But a few things are worth a prompt call rather than an “I’ll mention it next visit”: 

• New numbness or tingling that isn’t going away
• Memory or concentration problems that come on fast
• A heart that’s racing or pounding along with shortness of breath at rest

B12-related nerve damage is treatable, but the earlier it’s caught, the better your odds of treating it. Autoimmune gastritis is one of those conditions that hides in plain sight, dressed up as fatigue or brushed off as “diabetes stuff.” But you know better than that! The longer you’ve lived with T1D, the more you realize that sometimes there’s more going on, and not everything in your life, body or health is connected directly to it. If you feel like there’s more to your health story, that’s worth questioning.

Learning to recognize the signs your body is warning you about is exactly the kind of early awareness Beyond Type 1’s #SeeTheSigns campaign is built around. Take a look, and pass it along to anyone in your life who might be brushing off symptoms that deserve a second look.