Freed of the insidious pressure of uncertainty, the families of the 52 former hostages were immediately faced with a new phalanx of problems yesterday as their relatives suddenly were elevated to the status of national heroes.

All at once, they were being called on to decide whether to meet their relatives in Germany, to comprehend the first details of the sometimes cruel captivity, to plan for a long round of celebrations and to cope with reporters newly hungry for details of the ordeal.

One relative, the mother of hostage Sgt. Regis Ragan, was admitted to the coronary care unit of Lee Hospital in Johnstown, Pa., suffering from an apparent heart attack. Anna Ragan, 70, was reported in critical but stable condition yesterday afternoon. Her family, continuing the practice begun when the hostages were first seized in November 1979, refused to discuss their situation.

Once the hostages were on their way out of Tehran Tuesday, three of their relatives decided not to wait for a reunion in the United States, and borded planes for Germany, planning to meet the freed hostages in Wiesbaden.

Elizabeth Keough, former wife of hostage William F. Keough Jr., traveled there with her eldest daughter, Alyssa.

Lewis Hohman, brother of hostage Donald R. Hohman, left for Frankfurt as soon as he heard that the plane carrying the hostasges had cleared Iranian airspace.

The vast majority of family members, however, said they were not going or remained undecided yesterday, waiting to hear from their relatives for a second or third time before making up their minds.

"It is much more sensible not to [go to Germany]," said Katherine Keough, president of the families' umbrella organization, Flag (Family Liaison Action Group), and the present wife of Wiliam Keough. The arrangements for a reunion at an undisclosed location "are going to work out very well for the families," she said.

Former hostage Kathryn Koob told her sister yesterday that she was all in favor of the State Department's plan to allow the hostages to "decompress" at the Air Force hospital in Wiesbaden for several days.

"One of the first things she said to me was that this time in germany alone was absolutely essential and that whoever . . . thought it up was brilliant," said Koob's sister, Mary Jane Engquist.

However, at least one of the former hostages, Richard Morefield, told his family that he wanted to see them as soon as possible, according to his wife, Dorothea. Whether that reunion would take place in this country or abroad had not been decided, she said.

While trying to plan private reunions and homecomings, relatives were also trying to cope with the thanksgiving outpourings of their countrymen and the renewed eagerness of reporters anxious to gather up details about the newest national heroes.

Some reacted to the hostages' release by being open to media queries for the first time since the ordeal began. Others chose to remain silent, and some families lashed out bitterly at the intrusions.

Ari Benjamin, brother of former hostage Bruce W. German, said a reporter had taken the telephone from his mother's hand as she was talking to her son for the first time in more than a year. The reporter, Benjamin said, "began pumpimg Bruce with questions. This really infuriated him."

But former hostage German was already inclined to distrust the media, Benjamin said. Last April, while still a hostage, he received a telephone call from someone claiming to be his brother. The militants allowed him to take the call, Benjamin said, and the caller "started asking a lot of questions. Bruce realized that it wasn't me and that it must be a reporter. He hung up.

"When the militants realized what had happened, they never let him receive another phone call, and they stopped delivering mail from me to him or allowing his letters to me to get out."

Clara Holland, mother of former hostage Leland J. Holland, said that she was becoming infuriated bythe persistent ringing of the telephone in her Scales Mound, Ill., home. "I'm not going to take much more of it," she said.

At the same time they were trying to handle the media, the relatives were beginning to focus on the scope of national joy at the hostage's release -- and the plethora of celebrations it has spawned.

Officials of New York City have promised the former hostages its traditional hero's welcome, the ticker-tape parade, if President Reagan approves. In Pittsburgh, Mayor Richard Caliguiri declared yesterday "Hostage Freedom Day," and urged all city residents to display the flag. San Francisco was immersed in the cacophony of "Welcome Home Week," kicked off with wailing sirens and the insistent honking of horns.

Little Rock, the home of former hostage Steven Kirtley, plans a huge "Welcome Home Celebration" for the Marine Lance corporal.

The NBC television network invited all 52 hostages to the Super Bowl in New Orleans Sunday, while the executives of organized baseball offered them free liftime passes to all American, National and minor league games. And the Miami City Convention Bureau offered the freed Americans and their immediate families an all-expenses-paid week in the city with an airline, a hotel and a radio station paying the bills.

The Civil Aeronautics Board also cleared the way yesterday for any U.S. commercial airline to offer the returning hostages free domestic air trips for up to 30 days after their return.

Against the backdrop of national celebration, of pealing bells, waving flags and a profusion of yellow ribbons, most relatives were still concentrating on their own small plans: what they would cook, where they would go, what they would do when everything quieted down.

Theresa Lodeski, mother of hostage Bruce German, said she was going to make his favorite dishes -- lobster and cole slaw. "I'm going right down to the fish store and buy some Australian lobster," she said.

When he made his first telephone call home in 14 1/2 months, Kevin Hermening asked his mother, Barbara Timm, to have some breaded and barbecued pork chops waiting for him when he returned to Oak Creek, Wis. "He said he didn't want chicken legs or rice for his first meal," said Timm, apparently referring to the main bill of fare for the hostages in Iran.

Many of the hostages' first telephone calls home had some gentle tenor, suffused with trivia and affection. The returning Americans talked about future football games, about missed family milestones and doings of old friends. The words didn't really matter: just hearing the voices gave their relatives the proof that the wait was almost over.

"Hi, honey," former hostage Robert Ode, 65, told his sleepy wife as she picked up the telephone in her bedroom at 1 a.m. The rest of the conversation, she said, passed in a blur of endearments, affection and small talk. When she awoke yesterday morning, she said, she could remember little but the joy.

"I was glad, I was happy," said Helen Swift, mother of hostage Elizabeth Ann Swift. "She's just fine!" Her daughter's first words had long since slipped from her mind in the excitement of hearing that the voice coming into her Northwest Washington home.

"He sounded like he'd never been gone," said Kathryn Barnes of Falls Church after she talked to her son, C. Cortlandt Barnes, early yesterday. "He sounds just grand, and he looked beautiful."