Antigovernment forces are inflicting on Nicaragua a severe cost, both human and economic, according to officials here.
The cost takes several forms:
* Hundreds of casualties among soldiers and militiamen in the northern part of Nicaragua.
* Extensive evacuations of civilians away from areas bordering Honduras.
* A decline in the production of coffee and tobacco - both export and imports.
In an economic sense, the biggest cost of all may be the dislocation of resources caused by the fighting. The government has had to divert scarce funds into military spending and away from its hard-pressed economy.
In addition, diplomats speak of another cost that is impossible to quantify. Some of these officials say raids by the anti-Sandinista forces tend to strengthen the hand of ideological ''hard-liners'' in the Nicaraguan government and tend to weaken that of ''moderates'' who favor pragmatic approaches to the country's problems. The hard-liners can argue that because of the threat to the nation, personal freedoms must be restricted.
The United States is widely alleged to be supporting the anti-Sandinista forces and attempting to isolate Nicaragua by shoring up its neighbors. ''Ronald Reagan has been doing whatever he can to prove that this is a Marxist government ,'' said a Nicaraguan official. He added that by putting pressure on Nicaragua, the United States leader ''could make this a self-fulfilling prophecy.''
No one outside the highest reaches of the Nicaraguan government, meanwhile, seems to know the full extent of the damage caused by the anti-Sandinista forces operating in the northern part of the country. Publicly reported losses of soldiers who have fallen in the north in this year alone run into the hundreds. Some attacks are never reported by the press here.
In a speech a few days ago, the Nicaraguan defense minister, Humberto Ortega Saavedra, mentioned a number of attacks that previously had not been reported.
What appears clear is that the attacks have intensified in recent weeks. According to Nicaraguan press reports, the units of former Nicaraguan national guardsmen launching raids into Nicaragua from bases in Honduras have been increasing in size.
On Dec. 13, the Defense Ministry issued a communique saying that on Dec. 8, 400 ''counterrevolutionaries'' had launched an attack from Honduras into the northeast Jalapa region. The communique said that the attackers were trying to occupy a village. As seen from here, one of the attackers' main aims has been to occupy a piece of territory that they could then declare to be a ''liberated zone.''
In this case, the combat continued for five days. According to the Defense Ministry communique, the attackers were driven back into Honduras. Their losses were reported as 13 killed and 13 wounded. Losses among Sandinista soldiers were reported as seven killed and 11 wounded.
Meanwhile, evacuations of Miskito Indians away from the northern areas are continuing. In 1981, Nicaraguan government pressure on a number of Miskito Indian communities caused thousands to flee to Honduras. The government forcibly moved thousands of others south of the battle zone.
In the early stages, it appears that most of the Indian communities were opposed to being moved, even though the living conditions in the camps to which they were being moved were an improvement in some ways over their old homes. It now appears that because of the fighting, some of the Miskitos have been asking the Nicaraguan authorities to move them away from the Honduran border zone.
On Dec. 9, a Nicaraguan military helicopter carrying Miskito children on an evacuation flight crashed, killing 75 of the children. It was one of the worst air crashes in Central American history. The Nicaraguan government immediately blamed the Reagan administration for the crash because of its alleged support for counterrevolutionaries operating in the region. It did not go so far as to say, however, that the counterrevolutionaries had shot down the helicopter.
Saul Arana Castellon, the official in charge of North American affairs at the Nicarguan Foreign Ministry, said that the government expected the Honduran-supported attacks against Nicaragua to continue for some time. In an interview, the Nicaraguan official said that the government saw no indication that United States policy toward Nicaragua had changed after George Shultz became secretary of state earlier this year. Mr. Arana further said that even if the Americans wanted to cut their support for attacks against Nicaragua, it would not be an easy thing to do.
''They allege that the attacks are not intended to overthrow our government, '' said the Nicaraguan official. ''But the action is out of control. . . . It's a little monster that they've created.''