COVID-19 can disrupt the immune system in ways that may trigger or unmask autoimmune diseases in susceptible people, including Sjögren’s syndrome. While most people with Long COVID who develop dry eyes or dry mouth do nothave Sjögren’s, research suggests SARS-CoV-2 may contribute to autoimmune processes through immune dysregulation and abnormal B-cell activation. If persistent dryness is accompanied by symptoms such as joint swelling, Raynaud’s phenomenon, swollen salivary glands or positive autoimmune blood tests, further assessment may be appropriate.
Key Facts
- Long COVID and Sjögren’s syndrome share many symptoms, including fatigue, dry eyes, dry mouth and dysautonomia.
- COVID-19 may trigger or unmask autoimmune diseases in genetically susceptible people.
- Dry eyes and dry mouth after COVID do not automatically mean you have Sjögren’s syndrome.
- Diagnosis is based on the whole clinical picture, not one symptom or one blood test.
- Researchers are still investigating how SARS-CoV-2 may contribute to autoimmunity.
“Is This Still Long COVID… Or Is It Something Else?”
When you first develop Long COVID, almost every new symptom feels connected. The exhaustion.
The brain fog. The dizziness. The strange aches that seem to move around your body.
After a while, you almost stop questioning them because you’ve learned that Long COVID can affect nearly every organ and every system.
Then something different happens. Your eyes start feeling gritty every day, not just after a long day at the computer. You wake up during the night desperate for water because your mouth feels so dry. Your dentist asks whether you’ve started taking new medication because your teeth suddenly seem more vulnerable to decay.
At first, it’s easy to dismiss. Just another Long COVID symptom.
But weeks turn into months, and instead of disappearing, the dryness becomes part of everyday life.
You buy eye drops in bulk. You never leave the house without a bottle of water. Eating dry food becomes surprisingly difficult.
Eventually, curiosity turns into concern. You start searching online. “Can COVID cause Sjögren’s syndrome?”
It’s a question more people are asking than ever before.
Here’s Where Things Become Confusing
Long COVID and Sjögren’s syndrome have an extraordinary amount in common.
Both can cause profound fatigue, brain fog, muscle and joint pain, dry eyes, dry mouth and problems with the autonomic nervous system, leading to symptoms such as dizziness, palpitations and heat intolerance.
That’s one reason diagnosis can be so difficult.
Many people with Long COVID worry they’ve developed Sjögren’s syndrome.
Others are eventually diagnosed with Sjögren’s and wonder whether COVID triggered it.
And some people, like myself, end up living with both.
The challenge is that these conditions don’t just look similar—they can genuinely overlap.
The Biggest Misconception
Here’s the mistake many of us make. We assume the question is: “Do I have Long COVID or Sjögren’s syndrome?”
In reality, that’s often the wrong question.Long COVID can cause dry eyes and dry mouth without autoimmune disease.COVID may also reveal an autoimmune disease that had been quietly developing for years.
Or, in some people, both conditions may exist at the same time. Those three situations can look almost identical in the beginning.
That’s why doctors don’t diagnose Sjögren’s because someone develops a dry mouth after COVID. They look for a pattern. Has the dryness become persistent? Have new symptoms appeared alongside it?
Are there signs of autoimmune activity on blood tests?
Has the story changed over time?
That’s where the investigation really begins.
So, Can COVID Actually Trigger Sjögren’s Syndrome?
The short answer is:
Possibly.
The longer answer is much more interesting.
Doctors have known for decades that viruses can sometimes play a role in autoimmune diseases. COVID-19 isn’t the first infection to raise these questions. Viruses such as Epstein-Barr virus (EBV), hepatitis C and parvovirus have all been investigated as possible triggers for autoimmune conditions, including Sjögren’s syndrome.
The important word, however, is trigger.
A trigger isn’t the same as a cause.
Imagine someone has spent years slowly stacking dominoes. One final push eventually knocks them over, but that last domino wasn’t responsible for building the entire chain.
Researchers think COVID may work in a similar way.
For some people, the immune system returns to normal after the infection.
For others, COVID appears to leave the immune system unusually active for months, sometimes even years. Scientists have found evidence of persistent inflammation, abnormal B-cell activation and the production of autoantibodies in a proportion of people with Long COVID. These are all biological changes that are also seen in autoimmune diseases.
This doesn’t prove that COVID causes Sjögren’s syndrome.
But it helps explain why doctors are taking the connection seriously.
It May Be More Accurate to Say COVID Reveals Sjögren’s
This is a subtle but important distinction.
Most autoimmune diseases don’t appear overnight.
Long before someone develops noticeable symptoms, the immune system may already be changing quietly in the background. Autoantibodies can sometimes be present for years before a diagnosis is made, even though the person feels completely well.
COVID may simply speed up that process.
Instead of creating Sjögren’s syndrome from nothing, the infection may bring forward symptoms that would otherwise have appeared much later—or perhaps never become severe enough to attract medical attention.
That would explain why two people can have exactly the same COVID infection yet experience completely different outcomes.
One recovers fully.
Another develops Long COVID.
A third is eventually diagnosed with an autoimmune disease.
The virus is the same.
The immune systems are not.
Another Reason These Conditions Look So Similar
When people think about Sjögren’s syndrome, they usually think about dry eyes and dry mouth.
In reality, it’s a systemic autoimmune disease that can affect nerves, blood vessels, joints, lungs and many other organs.
One of the biggest overlaps with Long COVID is dysautonomia.
Both conditions can interfere with the autonomic nervous system—the network that controls heart rate, blood pressure, digestion, sweating and temperature regulation without us having to think about it.
As a result, both can cause dizziness when standing, palpitations, exercise intolerance, heat intolerance, digestive problems and overwhelming fatigue. Some people develop POTS, while others experience different forms of autonomic dysfunction that don’t fit neatly into one diagnosis.
This is one reason distinguishing Long COVID from Sjögren’s can be surprisingly difficult.
If someone develops dizziness, rapid heart rate and fatigue after COVID, those symptoms are often attributed to Long COVID alone. But in some cases, they may also be part of an underlying autoimmune disease that has been unmasked by the infection.
Recognising that possibility doesn’t mean assuming every symptom is autoimmune.
It simply reminds us that persistent symptoms deserve an open mind.
So, What Should You Do If This Sounds Familiar?
If you’ve recognised yourself in this article, don’t panic.
One of the biggest mistakes people make is assuming that every new symptom after COVID must mean they’ve developed another disease. The opposite can happen too—people are sometimes told that every new symptom is “just Long COVID,” when something else deserves investigating.
The truth usually sits somewhere in the middle.
If your dry eyes or dry mouth are mild, fluctuate from day to day and gradually improve alongside your other Long COVID symptoms, they’re less likely to suggest Sjögren’s syndrome.
But if the pattern keeps changing rather than settling—if the dryness becomes persistent, if your salivary glands swell, if your joints become inflamed rather than simply achy, or if autoimmune blood tests become positive—it’s worth discussing this with your GP.
Not because you should expect a diagnosis of Sjögren’s.
Because persistent symptoms deserve an explanation.
Your GP may decide to arrange blood tests such as ANA, anti-Ro (SSA) and anti-La (SSB), or refer you to a rheumatologist if the overall picture suggests an autoimmune condition. In some cases, further tests such as tear production measurements or a minor salivary gland biopsy may also be recommended.
It’s important to remember that no single test confirms or excludes Sjögren’s syndrome. Doctors build the diagnosis by putting together your symptoms, examination findings and investigation results over time.
Sometimes the answer is straightforward.
Often it isn’t.
The Bigger Picture
One of the most important lessons from the past few years is that COVID-19 doesn’t always fit neatly into one box.
For some people, it causes a prolonged post-viral illness that gradually improves.
For others, it appears to disturb the immune system in ways we’re only beginning to understand.
And for a small number of people, it may uncover an autoimmune disease that was already quietly developing beneath the surface.
That doesn’t mean COVID is the sole cause of Sjögren’s syndrome.
Nor does it mean everyone with dry eyes or dry mouth after COVID has an autoimmune disease.
What it does mean is that clinicians—and patients—need to keep an open mind.
As researchers continue to study Long COVID, the boundaries between infection, immune dysfunction and autoimmunity are becoming less distinct than we once believed.
Final Thoughts
If there’s one message to take away from this article, it’s this:
Long COVID and Sjögren’s syndrome are not the same condition—but they can look remarkably alike.
Both can cause fatigue, brain fog, dysautonomia, joint pain and persistent dryness. Both can have a profound impact on daily life. And in some people, they may even coexist.
The challenge isn’t trying to decide whether every symptom belongs to one diagnosis or the other.
It’s recognising when the story changes.
If your symptoms continue to evolve, don’t be afraid to ask questions or seek further assessment. Most people with Long COVID will never develop Sjögren’s syndrome, but for those who do, an earlier diagnosis can lead to better symptom management and appropriate long-term care.
The science is still evolving.
What matters today is making sure that persistent symptoms are listened to—not dismissed.
COVID-19 can disrupt the immune system in ways that may trigger or unmask autoimmune diseases in
Frequently Asked Questions
Can COVID-19 trigger Sjögren’s syndrome?
Possibly. Current research suggests that COVID-19 may trigger or unmask Sjögren’s syndrome in a small number of genetically susceptible individuals through immune dysregulation and persistent inflammation. More research is still needed to confirm this relationship.
Does dry mouth after COVID mean I have Sjögren’s?
No. Long COVID itself can cause dry eyes and dry mouth without autoimmune disease. Persistent symptoms, particularly when accompanied by positive autoimmune blood tests, swollen salivary glands or inflammatory joint pain, should be assessed by a healthcare professional.
What blood tests are used to diagnose Sjögren’s syndrome?
Doctors commonly test for anti-Ro (SSA) and anti-La (SSB) antibodies, alongside ANA and other markers of autoimmune disease. However, diagnosis is based on the overall clinical picture rather than blood tests alone.
Can you have both Long COVID and Sjögren’s syndrome?
Yes. Some people develop Long COVID despite already having Sjögren’s syndrome, while others receive a new diagnosis of Sjögren’s after COVID-19. The two conditions can coexist and share many symptoms, making diagnosis challenging.
Can Long COVID mimic Sjögren’s syndrome?
Yes. Long COVID can cause symptoms such as fatigue, dry eyes, dry mouth and autonomic dysfunction that closely resemble Sjögren’s syndrome, even when autoimmune tests remain negative. This is why a thorough medical assessment is important rather than relying on symptoms alone.
Medical Disclaimer
The information in this article is for educational purposes only and should not be considered medical advice. While current research suggests that COVID-19 may trigger or unmask autoimmune diseases such as Sjögren’s syndrome in some individuals, this relationship is still being actively studied. If you have persistent dry eyes, dry mouth, joint pain, fatigue, or other concerning symptoms after COVID-19, speak to your GP or a healthcare professional for a full assessment and appropriate investigations. Never ignore new or worsening symptoms or delay seeking medical advice based on information you have read online.
References
- Wang EY, Mao T, Klein J, et al. Diverse functional autoantibodies in patients with COVID-19. Nature. 2021;595:283–288.
- Vlachoyiannopoulos PG, et al. Autoimmunity and COVID-19: Current evidence and future perspectives. Nature Reviews Rheumatology. 2022.
- Mariette X, Criswell LA. Primary Sjögren’s Syndrome. New England Journal of Medicine. 2018;378:931–939.
- Baer AN, Hammitt KM. Sjögren’s Disease. The Lancet. 2024.
- Tezcan ME, et al. SARS-CoV-2 infection as a trigger for autoimmune disease. Autoimmunity Reviews. 2023.
- Brito-Zerón P, Baldini C, Bootsma H, et al. Sjögren syndrome. Nature Reviews Disease Primers. 2016.
- World Health Organization. Post COVID-19 condition (Long COVID).
- National Institute for Health and Care Excellence (NICE). COVID-19 rapid guideline
Related Articles
- Can COVID Trigger Autoimmune Diseases? Understanding the Evidence
- EBV Reactivation and Long COVID: Is There a Connection?
- Understanding Dysautonomia in Long COVID
- Why Does Long COVID Cause Dry Eyes and Dry Mouth?
- Post-Exertional Malaise (PEM): Why Activity Can Make Long COVID Worse
- Autoantibodies in Long COVID: What Do They Mean?
- Understanding Brain Fog in Long COVID
3 thoughts on “Can COVID Trigger Sjögren’s Syndrome? Symptoms, Causes and What We Know”