6 widely-believed diseases that don’t actually exist

The pitfalls along the way to a diagnosis are many. Thousands of diseases have overlapping symptoms, plus medical information can be missing, skewed, and siloed. On top of this, science never stops changing—it continually uncovers new diseases, symptoms, and unique case studies that change the status quo.

Medicine is an imperfect science. It improves with time, but history teaches us that there will always be knowledge that remains just out of reach. To fill the gaps, many people weave their own dubious diagnostic tales, relying on their anecdotal experience rather than empirical evidence.

The six diseases below are perfect examples. They may feel real—patients commonly complain of legitimate symptoms like nausea, fatigue, and irritability—but they don’t actually exist.

Wilson’s syndrome

First identified by family physician E. Denis Wilson, MD, in 1990, Wilson’s syndrome describes a collection of non-specific symptoms including fatigue, hair loss, depression, weight gain, brittle nails, and insomnia. Dr. Wilson said he developed the condition after observing patients who presented with these symptoms along with low body temperature. He claimed that the syndrome was a result of thyroid dysfunction, despite patients’ blood tests showing normal thyroid levels.

To date, there is no solid evidence in the medical literature to support the existence of Wilson’s syndrome. It is especially difficult to substantiate as a medical diagnosis because the symptoms attributed to Wilson’s syndrome are common in many other illnesses, or may even be a part of one’s normal life. A statement released by the American Thyroid Association dismissed the existence of Wilson’s syndrome, citing a lack of scientific evidence.

Leaky gut syndrome

Also known as increased intestinal permeability, leaky gut syndrome is a digestive condition marked by a compromised gut lining that allows bacteria and toxins to penetrate the intestinal wall and course into the bloodstream. A healthy gut microbiota—a collection of 100 trillion bacteria and microbes that inhabit the intestines—promotes a strong immune system and lower levels of inflammation. When gut bacteria become unbalanced, typically due to stress, heavy alcohol use, or a diet high in sugar and saturated fats, gastrointestinal issues like Crohn’s disease and irritable bowel syndrome can occur.

However, there is little compelling evidence to support that a “leaky” gut can cause significant health problems outside of the gastrointestinal tract. In fact, there is evidence that increased intestinal permeability actually has benefits, such as increased water and nutrient absorption and protective immunoregulatory processes. “It is always a good idea to a eat a nutritious, unprocessed diet that includes foods that help quell inflammation, which may, at least in theory, help to rebuild the gut lining and bring more balance to the gut flora,” wrote Marcelo Campos, MD, in Harvard Health Blog.

Candida hypersensitivity

Allegedly responsible for a long list of ailments that range from sexual dysfunction to asthma and psoriasis, candida hypersensitivity is caused by overgrowth of candida (Candida albicans), the naturally occurring yeast present in the body at all times. During periods of stress or when the immune system is compromised, proponents say the condition can lead to oral thrush or vaginal yeast infections. Anecdotally, candida overgrowth has been linked to hundreds of disorders, mostly without proof.

In a small clinical trial published in The New England Journal of Medicine, researchers recruited women who had chronic yeast infections and symptoms consistent with candida hypersensitivity, including fatigue, depression, and gastrointestinal issues. The women were split into two groups and given either antifungal medication or sugar pills. While the antifungal medication controlled the yeast overgrowth, it was not found to improve the reported symptoms any more than the sugar pills, suggesting that the symptoms were not related to candida overgrowth. According to the American Academy of Allergy and Immunology, the condition’s alleged connection to other illnesses is speculative and unproven.

Autistic enterocolitis

A controversial condition first reported by gastroenterologist Andrew Wakefield—who was also the first to suggest the widely debunked link between vaccines and autism—autistic enterocolitis is a syndrome of persistent gastrointestinal (GI) tract problems in individuals with autism. The frequency of GI problems in children varies from 9% to 37%, but ranges from 9% to 84% in children with autism spectrum disorder (ASD).

GI problems include diarrhea, bloating, abdominal pain, and constipation. Symptoms are sometimes difficult to assess in children with ASD because of difficulties in verbal and nonverbal communication, as well as an altered perception of pain. It is also understood that GI symptoms may overlap with core ASD symptoms. Despite these correlations, a causal scientific link between the two has not been found.

Hypoadrenia

Adrenal fatigue, or hypoadrenia, is thought to be characterized by an inadequate production of hormones in the adrenal glands, resulting from underlying medical conditions or stress. The symptoms of hypoadrenia are extensive and vague (similar to the other conditions in this article), including fatigue, body aches, lightheadedness, skin discoloration, and more. Proponents of hypoadrenia claim that it is often caused by chronic stress, which puts the body in a constant state of fight-or-flight. Under stress, the adrenal glands—which regulate the body’s immune system and metabolism—cause hormone dysfunction.

Adrenal insufficiency is a real disease that occurs when too little or too much of a hormone is produced, causing weight loss, fatigue, vomiting, and nausea. Hypoadrenia, on the other hand, a lesser form of adrenal insufficiency, is not a validated medical diagnosis.

Wind turbine syndrome

Wind turbine syndrome—a group of adverse health effects that result from living near industrial wind turbines—has been consistently dismissed as a conspiracy by scientists. Proponents of the syndrome, which is not recognized by the CDC, believe that infrasound—sound that is believed to be below the threshold for human hearing—emanates from wind turbines, causing symptoms such as disturbed sleep, ear ringing, rapid heartbeat, irritability, and anger.

The research, however, does not support this hypothesis. A study published in Health Psychology exposed participants to 10 minutes of either infrasound or sham infrasound. Beforehand, half of the participants watched footage designed to suggest that infrasound exposure caused specific symptoms. Within this group, a higher amount of people reported symptoms, despite being exposed to sham infrasound. But even if infrasound did cause medical issues, it is not exclusive to wind turbines.

“Everyone is surrounded by infrasound every day. It’s emitted by [harmless] natural sources like the surf, storms, wind itself, our own heartbeat and respiration,” said Simon Chapman, PhD, a professor emeritus of public health at the University of Sydney, in an interview with The Atlantic. “If wind turbines were harmful to nearby residents, entire cities and small nations would be stricken across much of Europe, where we see the highest density [of turbines].”