If barometric pressure has you baffled, if the Dow Jones average has you dizzy, if you're likely to lie about having read that 550-page report still sitting on your desk, you've got it bad, pal - INFORMATION ANXIETY.

Though it sounds like a Mel Brooks satire, author Richard Saul Wurman believes thousands, perhaps millions, suffer from the condition."It's saying, `I just can't keep up.' It's that feeling of pressure," said Wurman. "You know it, I know it. Admit it, everyone does," says the fast-talking author of "Information Anxiety" (Doubleday, $19.95).

"It's that feeling that Jerry Smith down the street can put together the bicycle and you don't know how; that THEY can program their VCR to record things 14 days ahead of time and you can't . . . that he's read the big, fat report sitting in your box and you can't because it just doesn't make any sense, so you have to lie and say, `Oh yeah, that was a pretty good report."'

That, says Wurman, is what society's latest high-tech malady has done - turned humans into masses of lying, quivering jelly brains, too afraid to admit they don't know, or don't understand.

Wurman argues that information anxiety is a result of the societal demand that everyone become a well-rounded cultural being, coupled with the fact that much of the information being dispersed does not really inform.

"It's just stuff, or data, and I refer to it as the non-information explosion."

Wurman blames the education system. He says schools teach that "it's better to say, `I know' than `I don't know.' It's better to answer a question than ask a question. . . . A longer report is a better report."

His new book is aimed at calming anxiety sufferers by providing such down-to-earth, common-sense ideas as:

- Allow that pile of periodicals stack up so high before ripping out individual articles of interest, thereby, reducing a preponderant pile to small stacks of what Wurman calls "interest shards." The idea: less to look at, less anxiety.

- Make a list of terms you use or hear often, but don't really understand (barometric pressure, the Dow Jones industrial average) and make a point to learn what they mean, one at a time.

- Never nod your head at something you don't understand. Practice saying, "I don't understand," in front of a mirror. The sooner you admit you don't know, the sooner you can actually learn.

The book, admits Wurman, is full of a lot of things that people always knew, but having them written in a book "gives it the kind of justification to say it out loud for the first time."

Wurman, who has an office in San Francisco and a loft-office in Manhattan, is an architect by training but is better known as an architect of information.

"I realize how ignorant I am," he said. "I'm more knowledgeable about my ignorance than perhaps anybody I know."

"When I don't understand things, I often do a book about them," says the 53-year-old writer, who has turned his thirst for knowledge into a thriving business.

The result has been 26 "Access" books that include guides to the 1984 Olympics, medical terms and his latest, a guide to The Wall Street Journal, which walks readers through a jungle of financial jargon.

He also is responsible for revamping the Pacific Bell Yellow Pages, listing goods and services other than alphabetically - by neighborhood and category, for example.

Though pessimistic about ending information anxiety, Wurman believes that within a decade the nation's data dilemma will spawn a new, multi-billion dollar industry: the understanding business.

"Newspapers will begin hiring people not just to style their newspapers but to make them understandable," he said. "Some bold news program on television will do that, and we'll actually have a weather map that you can understand.

"And business reports won't talk about M1s, M2s and M3s, which everybody thinks are bus lines. It will be information that people can use."

Because he understands this, he's gotten a jump on the competition and created a new business venture, The Understanding Business.

Now that's using common sense, which is what Wurman says his books, his business and his life is all about.

"I already told you," he says smiling, "I'm not that smart."