"It's like baking a cake"

May 6, 2005

Creative use of analogies, the author says, can help patients understand illness, treatment options, and the healing process.

Eighty-five-year-old Mrs. Johnson looked suspiciously at the prescription in her hand. She had no intention of taking the blood pressure medicine, she said, because it was "too strong a dose." She didn't buy my first explanation-that 25 mg of hydrochlorothiazide was much gentler than the 2.5 mg of Norvasc that had caused her dizziness and painful leg swelling.

So I tried another tack. "You've baked cakes, haven't you?" I said. "Norvasc is like the salt; a little bit goes a long way. This new water pill is like the sugar-a lot more is needed to get an effect." Mrs. Johnson returned the following week with lower blood pressure and no complaints about hydrochlorothiazide.

Metaphors can dramatically improve compliance because they present information in terms that patients can relate to. For example, if a patient refuses to take medication to control his high blood pressure because he has no symptoms, I explain, "It's like driving 55 mph in second gear. You can do it, but sooner or later you'll ruin the transmission. If you don't treat hypertension you'll strain your heart and blood vessels, possibly leading to heart failure or a stroke."

I also use metaphors when I encounter patients who insist that herbal remedies are preferable to conventional medicines because they're "natural." Before proceeding with an explanation of what I recommend for treatment, I point out that not everything in nature is beneficent; several types of mushrooms, for instance, are deadly.

Sometimes the same metaphor can apply to different circumstances. Take the woman who has had an abnormal Pap smear and needs HPV typing to determine her risk of cervical malignancy. "There are all types of dogs: poodles, pit bulls, and German shepherds," I tell her, "Each breed has a certain personality. Like dogs, HPV comes in many subtypes. Some are nasty and can pre-dispose to cancer of the cervix; others cause no known problems."

The dog analogy can also be useful for the patient who has been diagnosed with cancer. I explain how not all cancers are created equal; the prognosis and treatment depend on the specific variety of cancer. Most of what I say is not heard-the mind shuts off in a panic as soon as the patient hears the word "cancer." But patients seem to remember at the next visit that cancer is like a dog; there are different types. The unusual description helps with recall even when the circumstances are overwhelming.

A patient with a recently resolved sore throat might be concerned about remaining lymph node enlargement. Lymph nodes are like army barracks, I explain. They fill with soldier cells before the battle begins. Once the war has been won, the soldiers stick around a short time to keep the peace. The lymph node swelling is the last symptom to disappear because your body is trying to make sure you're protected against any remaining infection.

The war analogy also works well with patients who have allergies. "The body thinks pollen, cat dander, and other allergens are foreign invaders trying to take over," I say. "The immune system overreacts by sending kamikaze soldiers out to attack the invaders. The fighter cells self-destruct, releasing toxic chemicals. Sneezing, coughing, itching, and other allergy symptoms are the result of these chemicals. Allergy medicines prevent the fighter cells' self-destruction, so the damaging chemicals aren't released."

If a patient becomes alarmed by accumulated scar tissue from a fracture, I use an analogy to describe the healing process: To fix a hole in a wall, a construction worker mounds it full of plaster, then levels off the excess to make a smooth surface. The body deposits extra calcium in the area that needs to heal, then molds the surface into more even contours.