President Reagan has lots of worries these days, and some of them are getting in the way of the others.

In private conversations with aides and in comments that surface at his occasional news conferences, Reagan makes clear that he is fed up to various parts of his anatomy about "leaks" of any information that shows the administration in a less than favorable light.

His concern now amounts to "an obsession," in the words of one of his trusted aides, and was the basic reason for the promulgation first of White House guidelines designed to restrict the flow of information and then of an order that will make it easier to employ lie detector tests on any administration official with access to classified information.

The guidelines have proved silly and ineffective, and the lie detector order is potentially dangerous. But it doesn't seem to have occurred to Reagan that his obsession may be doing more damage to his administration than it ever will to the media.

In some of the same conversations in which he has expressed concern about supposed leaks, Reagan has also fretted that his support for genuine arms control negotiation is neither publicly understood nor accepted.

As the nuclear-freeze debate suggests, many Americans question the president's commitment to arms control despite his plan to eliminate all intermediate-range nuclear weapons from Europe. The president's own polls show an even greater public skepticism of his declared intention to reduce the strategic nuclear arsenals of the two superpowers.

Rather than trying to address these legitimate fears, Reagan and those close to him are throwing fuel on the fire. Last week, while administration officials were discussing a series of options for an interim proposal at Geneva that would reduce but not eliminate the intermediate-range nuclear missiles, the president and those close to him were searching for the sources who had provided this information to The Washington Post.

It was a strange investigation. Since West German, Italian and Dutch leaders had been briefed by the administration and announced their expectations to the world, there was nothing to keep from the Soviets. But Reagan and some of his intimates behaved as if the presidency would be sundered by news that he was actually considering a practical proposal for arms reduction.

There are other problems, too. At the same time that the administration is threatening to give lie detector tests or fire anyone who talks about even the most innocuous classified material, it was busily releasing exactly such information in an effort to demonstrate the massive nature of the Soviet military buildup.

The inherent contradiction was apparent to some administration officials, if not to the president.

"You run into a real difficult problem," one official said. "It is two sides of the same coin and no matter how you flip it, it's going to come up on one of those sides. If you don't release classified documents, your arguments aren't as good. And if you do, there is an absolutely valid argument that you are making a selective release of material to make your own case."

Reagan has not faced this issue squarely. He is relatively open in his dealings with aides, frequently making a comment that drifts into print and touches off a new search for "the leaker."

But he either does not understand or has not accepted the notion that inquiry into the process of an administration's decisions as well as the content of these decisions is a legitimate and inevitable field of journalistic inquiry in a free society.

Reagan's naive view of the issue of what should be told to the American people about his administration was best expressed after the resignation of Secretary of State Alexander M. Haig Jr. last June when the president said at a news conference, " . . . If I thought there was something involved in this that the American people needed to know, with regard to their own welfare, then I would be frank with the American people and tell them."

That's not the sort of decision that ought to be left to Big Brother.

Three top aides to the president--deputy chief of staff Michael K. Deaver, communications director David R. Gergen and presidential assistant Richard G. Darman--joined forces with CBS News correspondent Lesley Stahl last week to lighten White House tensions with a fake report about how White House chief of staff James A. Baker III was about to resign under pressure from conservatives.

The Stahl report became an overnight classic in the White House. It features a picture of a bare-chested Baker, undergoing a physical examination and supposedly suffering from anorexia nervosa, the starvation disease that mainly afflicts young women. At the end of this sequence, Stahl discloses that Baker is really being wired for a lie-detector test.

The gag didn't fool Baker, but it almost succeeded beyond the conspirators' wildest imaginations after an ABC employe overheard Stahl's deadpan report from the White House lawn. Soon, the White House was deluged with calls about "the resignation story" and had to deny it.

Baker struck back the next day. He called Thomas H. Wyman, president of CBS Inc., who called Stahl and told her that the White House was really upset at "the Baker story" and that she was in trouble at the network.

But when the chief of staff learned that Stahl had fallen hook, line and sinker for the counter-gag, he quickly called her and confessed