There’s plenty of blame to go around for this mess. But broadening our definition of disease probably made all of this possible.

My friend and colleague Dr. Beth Tarini, a health services researcher at the University of Michigan, published a study last year that examined how parents react when given a diagnosis of GERD for their infants. Dr. Tarini and her colleagues randomly chose certain parents to be told that an infant with symptoms of reflux had GERD or, instead, “a problem.” Half of each of these groups were also told that medications were ineffective.

Parents who were told that their infant had GERD were significantly more interested in having their child put on medication, even when they were told that medication was ineffective. Parents of infants who were not labeled with GERD were not interested in medication once they were told it didn’t work.

Words matter. Studies have shown that once people with high blood pressure are labeled “hypertensive,” they are significantly more likely to be absent from work, regardless of whether treatment was begun. Many diseases have become so much broader in definition that they now encompass huge swaths of the public.

When statins were first approved, they were used to treat people with very high levels of cholesterol. Their benefit was thought to be clear in that population. Last year, however, the release of new guidelines meant that more than 87 percent of all men age 60 to 75 would be recommended to be on statins, and the same for more than 53 percent of women in the same age group. Nearly every single African-American man over 65 would be recommended to be on the drug.

The American Academy of Pediatrics released guidelines a number of years ago recommending that children as young as 8 years old be treated with medication for an LDL cholesterol level above 190. Many think this is going too far. No one knows the long-term consequences of being on such drugs for decades.

Allowing the medicalization of normal variations in physiology to be transformed into “treatable conditions” is leading to unintended consequences. We’re spending billions of dollars on treatments that might not, or don’t, work. We’re making people worry when they don’t have to. And we may be causing actual health problems in the process.

As Dr. Tarini puts it, “Our job as doctors is to make sick patients healthy, not to make healthy patients sick.”