I'm a Doctor, Here Are The Hidden Signs You May Have an Autoimmune Disease
You might brush off the odd flare-up of fatigue, or blame digestive issues on something you ate-but your body has a way of quietly signaling when something deeper is going on.
An autoimmune disease occurs when the body's immune system mistakenly attacks its own healthy cells and tissues, leading to inflammation and damage in organs or systems, according to the Centers for Disease Control and Prevention (CDC).
Dr. Cory Rice, a medical doctor who specializes in the prevention, diagnosis and treatment of adult diseases, said these warning signs can easily go unnoticed for months-or even years-before a diagnosis is made.
“First and foremost, symptoms of autoimmune disease can come and go, and be on and off, or they can be more persistent in nature,” he told Newsweek.
In May 2025, Mayo Clinic researchers and collaborators found that about 15 million people in the U.S. are estimated to have one or more of 105 autoimmune diseases.
The Subtle Symptoms You Shouldn't Ignore
The most common autoimmune diseases include rheumatoid arthritis, psoriasis, type 1 diabetes, Graves' disease and autoimmune thyroiditis, states the Mayo Clinic.
From unexplained aches to persistent low energy, there are a number of early clues that could point to an underlying autoimmune condition.
Rice, an internist, shared the most common signs:
- Fatigue
- Low-grade fever
- Joint pain
- Unexplained rashes or hives
- Dry eyes and dry mouth
- Numbness or tingling in the hands or feet
- Mouth ulcers
- Increased sensitivity to cold temperatures
He said when people suffer from fatigue “it is usually both profound and debilitating.”
He notes that the patient may attempt to fix it by consuming stimulants and caffeine, taking hormones or thyroid medication or trying various IV therapies or B12 injections. But nothing works.
Why Diagnosis Can Take So Long
Autoimmune diseases are notoriously difficult to diagnose, in part because their symptoms can overlap with many other conditions.
“It all depends on the disease process in play and the severity or progression of the disease itself in a particular person as to whether symptoms are more constant or intermittent,” Rice said.
He added that many physicians are not routinely trained to screen for autoimmune diseases early on. As a result, patients are often referred to specialists, such as rheumatologists, for further investigation.
“Unfortunately, by this point, the autoimmune disease may already be far along in whichever parts of the body are impacted,” he said.
Rice emphasized that early diagnosis can significantly improve outcomes.
Common Myths Around Autoimmune Disease
Despite growing awareness, misconceptions about autoimmune disease remain widespread.
“The biggest myth I see is the belief that autoimmune disease is rare,” he said. “Nothing could be further from the truth.”
Newsweek also spoke to Gregg Silverman, a doctor, Lupus Research Alliance funded researcher and professor of medicine and pathology at NYU Grossman School of Medicine, who addressed another belief often shared by patients.
He said some people report that lupus began the day after a traumatic event, such as a car accident.
“I can't say for certain that such a story is a myth, I have assumed the patient has come to focus on the exact day the accident occurred and to link the accident with the appearance of symptoms like a rash or joint pain,” he said.
Silverman explained that some patients believe physical trauma directly triggers the disease.
“While it's possible, we don't think that is how autoimmune diseases really get started,” he said.
When To Pay Attention to Your Body
While the symptoms above can be concerning, experts stress that they do not automatically point to an autoimmune disease.
Many of these signs-such as fatigue or joint pain-are common and can be caused by a wide range of factors.
Experiencing one or even several of these symptoms does not necessarily mean you have an autoimmune condition, but if symptoms are persistent, unusual or worsening, it may be worth seeking medical advice.
Ultimately, being tired from time to time doesn't mean you have a disease-but consistently ignoring what your body is trying to tell you could delay getting the answers you need.
Contact Newsweek editors on this story: Charlotte Nisbet and Tony Phillips
2026 NEWSWEEK DIGITAL LLC.
This story was originally published July 5, 2026 at 12:00 PM.