People who worry excessively about their health tend to die earlier than those who don’t, a recent study from Sweden has found. It seems strange that hypochondriacs who, by definition, worry yet have nothing wrong with them, should enjoy shorter lifespans than the rest of us. Let’s find out more.

First, a word about terminology. The term “hypochondriac” is fast becoming pejorative. Instead, we medical professionals are encouraged to use the term illness anxiety disorder, or IAD. So, to avoid triggering our more sensitive readership, we ought to use this term.

We can define IAD as a mental health condition characterised by excessive worry about health, often with an unfounded belief that a serious medical condition is present. It may be associated with frequent visits to a doctor, or it may involve avoiding them altogether on the grounds that a real and quite possibly fatal condition might be diagnosed.

The latter variant strikes me as quite rational. A hospital is a dangerous place and you can die in a place like that.

IAD can be quite debilitating. A person with the condition will spend a lot of time worrying and visiting clinics and hospitals. It is costly to health systems because of time and diagnostic resources used and is quite stigmatising.

Busy healthcare professionals would much rather spend time treating people with “real conditions” and can often be quite dismissive. So can the public.

Now, about that study

The Swedish researchers tracked around 42,000 people (of whom 1,000 had IAD) over two decades. During that period, people with the disorder had an increased risk of death. (On average, worriers died five years younger than those who worried less.) Furthermore, the risk of death was increased from both natural and unnatural causes. Perhaps people with IAD have something wrong with them after all.

People with IAD dying of natural causes had increased mortality from cardiovascular causes, respiratory causes and unknown causes. Interestingly, they did not have an increased mortality from cancer. This seems odd because cancer anxiety is rife in this population. The principal cause of unnatural death in the IAD cohort was from suicide, with at least a fourfold increase over those without IAD.

So how do we explain these curious findings?

IAD is known to have a strong association with psychiatric disorders. As suicide risk is increased by psychiatric illness, then this finding seems quite reasonable. If we add in the fact that people with IAD may feel stigmatised and dismissed, then it follows that this may contribute to anxiety and depression, leading ultimately to suicide in some cases.

The increased risk of death from natural causes seems less easy to explain. There may be lifestyle factors. Alcohol, smoking and drug use are more common in anxious people and those with a psychiatric disorder. It is known that such vices can limit one’s longevity and so they may contribute to the increased mortality from IAD.

IAD is known to be more common in those who have had a family member with a serious illness. Since many serious illnesses have a genetic component, there may be good constitutional causes for this increase in mortality: lifespan is shortened by “faulty” genes.

What can we learn

Doctors need to be alert to the underlying health problems of patients and must listen with greater care. When we are dismissive of our patients, we can often be badly caught out. People with IAD may well have a hidden underlying disorder – an unpopular conclusion, I accept.

Perhaps we can illustrate this point with the case of the French novelist, Marcel Proust. Proust is often described by his biographers as a hypochondriac, yet he died in 1922 at the age of 51 at a time when the life expectancy of a Frenchman was 63.

During his life, he complained of numerous gastrointestinal symptoms such as fullness, bloating and vomiting, yet his medical attendants could find little wrong. In fact, what he described is consistent with gastroparesis.

This is a condition in which motility of the stomach is reduced and it empties more slowly than it should, causing it to overfill. This can lead to vomiting and with that comes a risk of inhaling vomit, leading to aspiration pneumonia and Proust is known to have died of complications of pneumonia.

Finally, a word of caution: writing about IAD can be quite risky. The French playwright Molière wrote Le Malade Imaginaire (The Imaginary Invalid), a play about a hypochondriac called Argan who tries to get his daughter to marry a doctor in order to reduce his medical bills. As for Molière, he died at the fourth performance of his work. Mock hypochondriacs at your peril.

Stephen Hughes is Senior Lecturer in Medicine, Anglia Ruskin University.

This article was first published on The Conversation.