By Katherine Hobson

At the beginning of his new book, “Overdiagnosed,” Dartmouth professor H. Gilbert Welch imagines all the medical diagnoses he might receive if he were given a thorough physical — borderline hypertension, overweight, benign prostate enlargement, degenerative joint disease and a few others — even though he generally feels pretty good.

Welch and co-authors Lisa Schwartz and Steven Woloshin, also of Dartmouth, write about the hazards of looking too hard for conditions or illnesses in healthy people, including additional procedures that carry no benefit but may cause harm, higher health-care costs and the psychological impact of being told you’re sick. We chatted recently with Welch. Here are edited excerpts:

What is overdiagnosis?

Overdiagnosis occurs when physicians make a diagnosis in an individual who would never go on to develop symptoms or die from the condition. it happens when we try to make diagnoses too early, in people who don’t have symptoms. I’m not saying we should never do that, but members of the general public have gotten the message that early diagnosis is always in your best interest, that it’s always good to look harder and find more. but the reality now is that we can find abnormalities in just about everyone and that can start a whole train of harmful events. so we all need to adopt a more balanced approach. Overdiagnosis doesn’t necessarily lead to overtreatment, but it often does.

How do you define health?

Health is much more than not being able to find something wrong. It’s how people feel, it’s a state of mind. and it’s hard to feel good when things are constantly being found wrong with you. but we are moving towards a [notion of] health that means the absence of any abnormalities. That’s not a good definition.

The book discusses overdiagnosis in a range of medical settings, including cancer. Where did the problem start?

I say it starts with hypertension, though some doctors might argue with me. but that’s the first place where we really started looking for abnormalities in a broad way. I’m not saying nobody with high blood pressure should be treated, I’m just saying it was an incredible paradigm shift to start looking for [problems] in people who were apparently well. In hypertension we had really persuasive data about the value of treating people with really high blood pressure. It’s incredibly important to treat them. The question is how we define abnormal and what warrants treatment. and we have progressively gotten interested in treating people with lower and lower blood pressure.

Is this problem acknowledged?

When I first wrote about the problem of overdiagnosis in cancer I got the sense that doctors thought I was crazy. but [the issue of overdiagnosis] in prostate cancer woke physicians up to this general problem.

So when your physician offers you a test, what should you do?

First get a sense of how you feel about this issue. some people prefer to look as hard as they can for anything that might cause problems in the future with the hope of avoiding those outcomes, understanding that the price they’ll pay for this is a vast increase in being told about things that won’t matter. that may mean unnecessary treatment and side effects. Other people may feel they’re well as long as they feel well and won’t [get screened and tested for everything], accepting the fact that perhaps they’ll miss some benefit of finding something early. see where you sit on this spectrum and communicate with your doctor.

When a specific test is being offered or suggested, ask why the physician is recommending it — that may lead to an interesting discussion. Ask whether the physician him- or herself has the test. and ask what randomized trials show about how it helps in the long run, how much evidence there is to support that and how many people are overtreated.

Living in Alachua County, we are more than 40 percent more likely to die of diabetes than residents in the rest of Florida. the odds are worse if we’re African American. between 2006 and 2008, the age-adjusted death rate from diabetes was 155 percent higher for black residents than for white residents.

Those figures are part of the 2010 Alachua County Health Needs Assessment. And the no. 1 factor behind the numbers? Obesity.

A report last week from the UnitedHealth Center for Health Reform & Modernization states than more than half of all Americans will have diabetes or pre-diabetes by 2020.

The health care costs of the diabetes epidemic could reach $3.35 trillion if current trends continue, the report warns.

We are growing fatter, and with obesity comes a phalanx of chronic health problems, including Type 2, or noninsulin-dependent diabetes.

The average health care costs in 2009 for a person with known diabetes totaled $11,700, compared to an average of $4,400 for the remainder of the population, United HealthCare reports.

Fortunately, diabetes is also one of those problems for which there is a solution. while there’s no cure, diabetes can be managed. Early screening helps. Healthier diets and more physical exercise are the two keys to controlling its potential health impacts, which are many and serious: heart attack, stroke, blindness, amputations and kidney failure.

Diabetes educators point out that there are two types of diabetes. Type 1 is an autoimmune disorder, genetically linked, in which the body attacks itself and destroys the cells in the pancreas that make insulin. People with this condition are usually diagnosed young and must receive insulin to live.

Type 2, or adult-onset diabetes, is reaching near-epidemic proportions. Obesity is a major risk factor, and those with it have trouble putting insulin to use in the body to metabolize dietary sugars. Type 2 diabetics face more complications, including high blood pressure, high cholesterol, heart disease and stroke.

Common symptoms include frequent urination, excessive thirst, extreme hunger, unusual weight loss or gain, increased fatigue, irritability, blurred vision and frequent infections.

With this type of diabetes, experts’ advice is simple: move more. Eat less.

However, as Diane Dimperio of the Alachua County Health Department points out, it isn’t always easy to follow that advice. Food temptation is everywhere, especially over the holidays. You may feel too rushed to fit regular exercise into your daily schedule. You may be the only one in the family cutting back on sweets and sodas.

There are local programs that can help, Dimperio said.

At the Alachua County Health Department, primary care specialists assist with medical management of your disease. There is also an enhanced program for diabetes management headed by an exercise physiologist for diabetics who come through the clinic. for some, the program provides free glucose testing strips.

“We are starting to acquire data to measure the success of this program,” Dimperio said, “but on a case-by-case basis, I can say we’ve seen a huge improvement.

Then there’s the CHOICES health education and wellness program, which offers exercise and nutrition classes in a group setting.

Participants don’t have to be enrolled in CHOICES to participate and classes are held “all over the county,” Dimperio said. Exercise options range from zumba and kickboxing to senior exercise, sports conditioning and pilates.

Here are some general tips worth following:

Lose weight if you are overweight.

Eat small, frequent meals to maintain blood sugars within healthy range.

Keep refined starches and sugars to a minimum.

Minimize consumption of saturated fats and trans-fats.

Eat lots of vegetables.

Increase your activity level. Aim for 30 minutes a day

“Take control; don’t be a statistic,” Dimperio said.