No aspect of life is immune to the law of unintended consequences. Medical care, in particular, often seems like a long cautionary tale on the ripple effect of seemingly small decisions.

A simple blood test can lead to thousands of dollars worth of further testing and possibly surgery. An imaging study can lead to biopsies and treatments for a cancer that may never have caused any problems.

Of course, that blood test can offer relief and peace-of-mind when it comes back normal. And the imaging study might discover a cancer that is truly life-threatening. So what do you do?

I can’t answer that question for you, and I won’t try. But many smart people have questioned some of the screening tests we consider routine. Here are a few you might want to ask some questions about before your doctor orders them for you.

Prostate Cancer Screening

It couldn’t seem more innocuous. A quick blood test, probably when they are already drawing blood to check your cholesterol, seems harmless. But that simple blood test can trigger a domino effect of further testing, interventions and treatments.

The blood test is looking for the level of Prostate Specific Antigen, PSA, in the blood. This marker is produced by the prostate gland, and it is often elevated in the case of prostate cancer.

The US Preventive Services Task Force (USPSTF) gives screening for prostate cancer with a PSA test a grade of “D.” This means they recommend against this test, and they do so with good reason.

First, PSA screening detects a fair amount of cancer that would probably never progress or cause symptoms for the man during his lifetime.

Second, there is no consensus on the appropriate intervention for localized prostate cancer.

Third, the reduction in mortality 10 to 14 years after screening is minimal. In other words, PSA screening isn’t doing much to prevent death from prostate cancer.

Fourth, the next steps in screening, which often include biopsy, carry risks such as infection and bleeding.

And finally, “Harms of treatment include erectile dysfunction, urinary incontinence, bowel dysfunction, and a small risk for premature death,” according to the USPSTF.

With the technology we have today, PSA testing for prostate cancer screening carries more risks than benefits.

Breast Cancer Screening

If there is one screening test that is associated with the most controversy, it’s screening mammography. This test is basically an x-ray of the breasts used to look for signs of breast cancer. I wrote about the varying opinions within the U.S. as well as in other countries last year. They range from recommending mammograms yearly for women over 40, to not recommending them at all, ever.

The USPSTF published new recommendations for screening mammography early this year. They give a grade of “C” for women aged 40 to 49, which means that providers should only offer it for selected patients. They give it a grade of “B” for women aged 50 to 74 because it appears to offer moderate benefit in this age group.

Not surprisingly the USPSTF has been criticized for overstating the benefit of screening mammography and understating it. This is a controversy that won’t go away any time soon. So what do you need to consider when you make this decision?

First, are you willing to go down the path of diagnosis and treatment of a positive mammogram? This could mean additional costs for further imaging studies, or biopsies with accompanying risks of bleeding and infection.

Are you willing to pursue surgery, chemo, and radiation? This might seem like an easy choice – if you have cancer, you get treatment. But what about ductal carcinoma in situ (DCIS)? This is Stage 0 breast cancer, meaning it’s limited to a milk duct. It may become an invasive cancer, or it may not. Of new breast cancer diagnoses, 83 percent are DCIS. There is no way to predict which will progress to a more dangerous disease and which will not. Are you still certain you want that cancer treatment?

The bottom line is women need to have this conversation with their doctors. Have them walk you through all the what-ifs. The decision isn’t about whether or not you mind having a mammogram, it’s whether you mind what your choice about mammograms can lead to.

Full Body Scan

You may have seen wellness centers offer full body scans in your area over the years. These centers offer scans of your entire body to look for early signs of cancer, among other things.

Most of these centers use a variation of computed tomography (CT) or PET scans. These methods both use radiation. Essentially they employ total body radiation to go on a fishing expedition.

It is interesting to note that not a single medical society recommends full body scans for healthy people. That’s because no benefits from the test have been proven. According to the FDA, “Whole-body CT screening has not been demonstrated to meet generally accepted criteria for an effective screening procedure.”

Moreover, your insurance probably won’t cover it. You will probably get more for your money with a gym membership and a bigger budget for fruits and vegetables.

A word about Screening vs. Diagnosis

Note this discussion revolves around “screening” tests. Screening tests are used to find disease in healthy people of average risk for the disease.

But if you have symptoms of an enlarged prostate, a family history of breast cancer, or a diagnosis of cancer that can spread to remote parts of the body, the story is different. You have either a known disease or a higher risk for disease. This means the typical criteria for screening tests no longer apply.

Any determination about testing for an individual with symptoms or increased risk of disease needs to happen within the context of that specific situation.

One Screening Test You Should Definitely Have

If you are a Baby Boomer, you should be tested for Hepatitis C. Transmission of this virus was highest during the 60s though the 80s, making Baby Boomers the generation that accounts for 3 of 4 infections.

While Hepatitis C can be spread through sharing needles or receiving contaminated blood products, a great many of those infected with the virus have no history that would put them at risk.

Those infected with Hepatitis C often have no symptoms for years, if ever. But if the infection does cause disease it is quite serious. It can lead to cirrhosis of the liver. It is also the leading cause of liver cancer.

With improved testing approved in 2010 and new treatments in 2013, there is much that can be done to prevent the worst outcomes of a Hepatitis C infection. If you were born between 1945 and 1965, you need to be tested once, so ask your doctor about it at your next visit.

In the end, no single group of screening tests is right for everyone. Examine your priorities and goals. Understand of the risks and benefits of the tests. Consult with a trusted healthcare provider. These are the steps that will lead to the best choices for you.

Amy Rogers MD is not a practicing physician and nothing written here should be taken as medical advice from either Amy or AssetBuilder. Medical decisions should be made with care in consultation with your health care provider.