Washington ? Toni Cordell-Seiple uses different-colored markers to carefully write “from lung doctor” or “for blood pressure” on her husband’s myriad prescription bottles.

It’s easier than stopping to decipher the 10-letter, almost unpronounceable drug names each time she grabs one of the lookalike bottles. It’s also something of a reflexive defense for the Georgia woman, who says she once read so poorly that she signed hospital forms unknowingly consenting to a hysterectomy.

“The personal humiliation that I had not understood it was too great to confess” until years later when the mother of three, who spent her youth with undiagnosed dyslexia, finally conquered reading.

Comprehending medical jargon is difficult, even intimidating, for the most educated of laymen. It’s almost impossible for millions of people who can’t read well, aren’t fluent in English or have vision or cognitive problems caused by aging. And the consequences of low health literacy can be devastating: more and longer hospitalizations, even death.

A major study in Florida is testing whether teaching health literacy classes and using simple-to-understand medical instructions including lots of pictures instead of big words and doctor-speak can keep Medicaid patients with diabetes and high blood pressure healthier.

But “low literacy is far more than a reading problem,” says Dr. David Baker of Chicago’s Northwestern University, citing studies that show patients who have a hard time comprehending health instructions avoid care.

“How can we get patients with limited literacy to be empowered and ask questions of their doctors, rather than just nodding their heads so that they’re not embarrassed because they think that the doctor is going to say that they’re dumb?” Baker asked.

The prestigious Institute of Medicine has just begun a study of how many Americans risk their health because they can’t understand hospital forms or medication labels or don’t know what to say when a doctor asks for their medical history.

Education statistics show one in five adults reads below the sixth-grade level, while most health materials are written at the 10th-grade level or above.

Then there’s the common lack of translations for immigrants, plus Barker’s research that suggests health literacy drops with old age.

Not to mention busy doctors who don’t take the time to fully explain how to treat or prevent a disease in words patients can understand. Why say “you have a benign tumor” instead of the clearer “it’s not cancer”? Or assume people know “take orally” means “by mouth”?

Even with instructions as simple as “take a pill three times a day,” “You would be maybe amazed at how many people really don’t understand that means breakfast, lunch and dinner,” Kim Lee of the Georgia Health Literacy Project said during a recent meeting of health communication specialists. The Georgia pilot program has begun teaching students in some adult reading classes how to interpret health instructions.

The question is just what will it take to improve such patients’ health: Do all pill bottles need picture instructions? At what reading level should health information be worded?

Enter the Florida Health Literacy Study, the first research to compare whether extra literacy steps keep at-risk patients measurably healthier than standard care.

Run by the University of South Florida and funded by drug manufacturer Pfizer Inc., the study has 27 community health centers enrolling up to 2,800 Florida Medicaid patients with diabetes or high blood pressure, two common diseases that can kill if not controlled properly.

For two years, half the centers will administer standard care. At the other half, patients will attend classes about their disease and receive special health materials, in English and Spanish, that are full of pictures and very easy words: the diabetic symptom “increased urination,” for example, is written as “having to pee a lot.” They also get real-world advice such as that a half-mile walk to the bus stop each day or salsa dancing every weekend is comparable to exercising at an expensive gym.

However the Florida study turns out, the head of an American Medical Assn. health-literacy program advises doctors to begin communicating better today. Dr. Joseph Riggs, a New Jersey gynecologist, makes his patients repeat treatment instructions back to him to ensure they understood.

“We can’t make them feel embarrassed and ashamed,” Riggs said. “We have to help them through this process.”