By Suzanne O'Sullivan

When I meet a patient with a complicated medical history, I often start by asking when they were last perfectly well. Darcie couldn't remember ever being truly well.

Darcie is 20 years old. She was referred to me because she was having regular seizures, but her illness began long before. It began with headaches as a child, which a neurologist diagnosed as migraine when she was 13. By the time she reached my office, her referral letter included hypermobile Ehlers Danlos syndrome (hEDS), anorexia, irritable bowel syndrome, postural orthostatic tachycardia syndrome (PoTS), autism, ADHD, depression and anxiety. She had also started having seizures every day, which was why she was in my clinic.

Darcie was clearly sick. She had barely been out of her own home for a year. Yet I came to believe that most of her symptoms, including her seizures and faints, were psychosomatic.

Every measure we took of Darcie's brain waves, heart rate and blood pressure was entirely normal. When Darcie felt dizzy and fainted, her blood pressure and heart rate were normal. This left only one explanation for why these normal measures contradicted Darcie's experience of her body: A psychological process rather than a disease process was making her collapse.

Most doctors who see a large volume of patients will regularly see young people with various mixes of Darcie's diagnoses. Other diagnoses in this pile include Tourette's syndrome, dyslexia and dyspraxia, mast cell activation syndrome (an immune disorder) and Chiari malformation (a developmental difference in the base of the skull).

What all of these diagnoses have in common is that they all have a severe form with a demonstrable pathology, like a genetic or biochemical abnormality, that's been recognized for decades, but have expanded in the past 20 to 30 years to include mild cases with no proven pathology. While there has been no real change in the share of people suffering from the severe form of these diseases, sufferers with the milder form have shot up dramatically. For example autism diagnoses in the U.K., where I work, rose by 787% between 1998 and 2018.

Because the line now between normal and abnormal for these diagnoses is often faint, some physicians fear that these labels pathologize healthy bodies, particularly in young people.

The symptoms Darcie suffered that worried specialists, such as her flexible joints and low blood pressure, are common features of young people's physiology. Time, historically, was the cure. It isn't clear that diagnosing ever more people with these ailments is actually helpful. In fact, there's good reason to believe it's doing harm.

Take Darcie's diagnosis of PoTS, a condition in which changes in posture provoke a fall in blood pressure that can cause fainting or dizziness. She earned this label at 17 when she fainted during a netball game on a hot day and an empty stomach; a nurse found her blood pressure was low.

But was this diagnosis helpful? It's easy to see how it might be counterproductive. A patient who is told they have an abnormal heart-rate response to standing may grow cautious about sudden movements and spend more time sitting down. This inactivity then makes the body respond more sluggishly to changes in posture, making a fall in blood pressure on standing more likely, increasing the chances of fainting. It's a vicious cycle.

Moving the parameters of 'normal' not only encourages people to seek medical attention for something they might not have medicalized before, it can also inspire some to unconsciously conform to a diagnosis's description. Basically, a label can encourage people to register symptoms they might have otherwise dismissed.

It is interesting to note that the labels of PoTS and hEDS didn't exist until the 1990s, but neither were there large numbers of people with these symptoms, as there are now. In fact I cannot recall meeting a single person with the specific constellation of symptoms that fit with these disorders until 15 or so years ago. The growing number of young people with PoTS and hEDS is a new population of patients.

Controversial disorders for which there is no proven pathology, including autism, ADHD and anxiety, often cluster together. Yet not enough people are asking how a growing group of young people like Darcie could be so unlucky as to have multiple apparently unrelated diagnoses. These disorders cannot be explained by a shared pathology -- otherwise people with severe autism and severe ADHD would have the same high rate of hEDS and PoTS as those with mild autism and mild ADHD. They don't.

The association between autism, hEDS, ADHD, PoTS, Tourette's, MCAS and Chiari malformations is only at the mild end of the spectrum, only in that gray area of diagnoses where it is hard to distinguish normal from abnormal. Their overlap can't be explained by biology, but by human psychology and the design of our medical systems.

People who worry about their health tend to worry about all aspects of their health. Once in the hospital system, they will have tests that pick up small differences that add to their concerns and see specialists who will try to appease them with a diagnosis. Once a perceived abnormality is found, doctors are compelled to keep looking, to monitor, to treat.

Once a person has a diagnosis, they often turn to illness groups, where they learn of other medical problems that might be on the horizon. Joining an illness support group can actually make symptoms worse by encouraging people to pay more worried attention to their body at a time when less attention is what they need. Embracing a group identity that centers around illness can pre-empt an identity that concentrates on recovery.

For those with moderate to severe problems, the benefits of a diagnosis are clear. My concern is with expanding diagnostic labels to include people at the mild end. The milder a medical problem is, the smaller the impact of any intervention and the greater the risk of harm from treatment.

The more I talked to Darcie, the clearer it was that more than just her seizures were psychosomatic. Everyone experiences physical symptoms when distressed, but hers were severe. Her headaches and stomachaches when she was upset spoke to her tendency to embody her feelings. Once this tendency had led her into the medical system, she was encouraged to pay attention to any bodily change. The more she was asked about symptoms, the more she looked for them. In seeking explanations, she received labels in return. All that did was heighten her health anxiety until she was so overwhelmed that she developed convulsions.

I would like to tell you that once I had established that Darcie's convulsions and faints were psychosomatic, I was able to reinvestigate and undo some of the diagnoses that had gone before. But Darcie's other diagnoses weren't considered within my remit. It seemed there was a good chance her hypermobile joints were just part of the normal range of how joints look, that her difficulties at school might be better explained by her many medical absences rather than by autism and ADHD. But Darcie found it hard enough to have her seizures called psychosomatic, so when I tried to address her other issues, she put me firmly in my place saying, "You're not an EDS doctor and you're not a PoTS doctor, so you have no right to look into those."

Darcie had a point. Specialists are encouraged to stay in their own lane. So all I could do was add my diagnosis of psychosomatic seizures to her already long list of other conditions. Darcie went home, presumed to have both PoTS and psychosomatic faints. Two diagnoses to explain the same blackouts.

Suzanne O'Sullivan is a neurologist working in the U.K. This is adapted from her new book, "The Age of Diagnosis: How Our Obsession with Medical Labels is Making Us Sicker," published by Penguin on March 18.

(END) Dow Jones Newswires

March 17, 2025 12:08 ET (16:08 GMT)

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