A 19-year-old student nurse was referred to me by a colleague for treatment of an overactive thyroid gland. About a year before, she had sought his advice for help with weight loss.  After several months of getting nowhere, the pounds began to come off dramatically. She lost 30 pounds over the next three months. Suspecting diabetes or even worse, her doctor undertook a workup that showed her weight loss was caused by hyperthyroidism, which placed her at risk of heart-rhythm problems and bone thinning.

Before subjecting her to treatment, which would involve radioactive iodine, I rechecked her lab tests and added a few of my own. The results were surprising.They indicated that she must be surreptitiously taking Cytomel, a form of thyroid hormone. When taken in large amounts, the drug can simulate the symptoms of an overactive thyroid, including prodigious weight loss. She wept as I confronted her and, after discussing the issue, agreed to my suggestion that she go for psychological counseling.

As long ago as 400 B.C. the fabled physician Hippocrates warned that patients often dissembled when saying they took their medicine. Over the years, I’ve found that quite a few take liberties with the truth in ways that can undermine a physician’s ability to correctly diagnose and treat a problem.


Why patients lie
Some patients do it because of shame, guilt, or fear of offending the physician. A depressed 65-year-old graphic designer, aware of my general bias against dietary supplements, never told me he was taking St. John’s wort, a dietary supplement used to treat mild depression. I prescribed a small dose of fluoxetine (Prozac and generic). It was weeks before we realized that the combination was what caused him to walk around in a fog.

A desire to impress can also prompt lying. People with diabetes are often on their best behavior for a few days before an office visit, so that their blood sugar will be near normal. This was the case with a 50-year-old construction worker who was dismayed when I asked to see his glucose monitor. There, in the memory of that mini-computer, were some of the worst glucose levels one could imagine.

Side effects prompt still other patients to stop medications without telling their doctor. Such a decision had disastrous effects for a patient who stopped his blood thinner because of a headache and wound up several days later with a stroke.

Last year Consumer Reports published a survey of doctors.What bugged them most about their patients was noncompliance with medication instructions. I recall a 50-year-old taxi driver whose blood pressure failed to improve despite three medications prescribed over a nine-month period. I was about to subject him to some expensive tests to find the reason for his “resistant” hypertension when he confessed that he had never filled even one prescription. Alas, many people with hypertension are loath to take medication because of the treatment’s side effects, which can include coughing, fatigue, frequent urination, rashes, and impotence. Some researchers estimate that as many as half of patients tell their doctors they are complying with medication instructions when in reality they aren’t. In one study using a device that recorded the date and time the medicine was taken, 73 percent of the patients said they used it three times a day. But when the information was downloaded, it showed that only 15 percent were doing as they said. Moreover, 14 percent had emptied their devices just before turning them in—to give the impression that they were compliant patients.


Truth be told
In the interest of good medical care and your own safety, it’s important to be honest with your physician at all times. As in any good relationship, the one between patient and physician must be based on mutual respect, trust, honesty, and transparency.

You will enjoy a better relationship with your doctor if you:

• Don’t underestimate your bad lifestyle choices—drinking, smoking, lack of exercise, poor eating habits.
• Do make the effort to be frank about embarrassing or touchy issues such as sex or finances.
• Don’t provide false information to please your doctor.
• Do carefully comply with medication instructions.
• Don’t start or stop medications without discussing it first.
• Do report your frustrations and dissatisfaction with the service or care.

This article first appeared in the November 2008 issue of Consumer Reports on Health.