The illegal use of cocaine has reached record levels throughout the Washington area, posing a virtually insurmountable challenge to police departments and a public health problem of nearly epidemic proportions, according to local and national law enforcement authorities and medical experts.

So widespread is the use of the highly addictive drug that experts now say that all segments of society here -- from the very rich to the very poor, from working women to unemployed teen-agers -- are suffering its effects and will do so for years to come.

Three days ago, University of Maryland basketball star Len Bias died of cardiac arrest. According to sources close to the investigation, traces of cocaine were found in Bias' urine samples. As a result of that disclosure, attention is once again focused on the drug that has ruined the careers of movie stars, professional athletes, musicians and countless less visible Americans.

"It's like an ocean -- everywhere we turn we see cocaine," said Capt. John F. Miller of the Rockville Police Department, which created its first full-time positions for narcotics investigations last summer to deal with the mushrooming cocaine trade in Maryland's second-largest city.

Once so expensive that it was out of most people's reach, cocaine now "is used in all age groups, by all races, both sexes and at all income levels," said Edgar H. Adams, director of the National Institute on Drug Abuse division of epidemiology and statistical analysis.

The drug now is sold openly on Washington's streets and almost as casually in a number of upscale bars in the city and the suburbs, according to police. And cocaine is now available in quantities small enough to cost only $10, $15 or $25 -- within the reach of many more potential buyers.

In the District and surrounding jurisdictions, the largely hidden problems of cocaine surface with disturbing and increasing frequency:

The National Institute on Drug Abuse reported last week that cocaine-related "episodes" in Washington area emergency rooms had more than doubled, from 302 in 1983, to 809 last year. In the District, police report a more than tenfold increase in arrests for the possession or distribution of cocaine since 1981, up to 1,735 last year.

Maryland, which the state government estimates has 50,000 cocaine addicts, will soon open the first government-funded clinic in the nation to assist indigent users of the drug. In Montgomery County, one of the wealthiest jurisdictions in the country, police made 96 cocaine-related arrests in the first four months of this year, compared with 130 in all of 1985. Suburban Hospital in Bethesda launched a cocaine hot line last month; 200 people telephoned for help the first night, and the service has averaged 40 calls per night since then.

In Virginia, whose bustling ports and intricate coastline are typical avenues for cocaine smuggling, officers of the U.S. Drug Enforcement Administration recently confiscated 700 pounds of cocaine in rural Bath County, the largest drug seizure in state history. In Fairfax County, cocaine-related arrests have doubled in the past five years to 162. Arlington County and Alexandria police recently ended a six-month investigation of cocaine sales at several trendy bars in the area, arresting 41 persons on cocaine charges.

Arlington police Lt. John S. Karinshak said those arrested included "some professionals, some mechanics, secretaries -- you name it."

There is no precise data on who uses or deals in cocaine in the Washington area, but officials at drug treatment centers, hot line volunteers and police and court officers agree that there are thousands of recreational users and addicts in the most comfortable suburban neighborhoods and the bleakest ghettos of the city.

Cocaine use has spread to small towns well outside the Capital Beltway, officials said. "In rural counties outside D.C., I talk to the local police, and I ask them what are their problems," said Bob O'Leary, a DEA spokesman.

"They all say cocaine," he said. "It's a 100 percent response. There is not a village safe from it."

Cocaine, which has been illegal in this country since 1914, is extracted from the leaves of the South American coca plant and has several legitimate medical uses. When ingested, it raises the body temperature and curbs the appetite. More significantly, it can produce rapid and erratic increases in a person's heart rate and blood pressure.

Those cardiovascular problems, according to some experts on cocaine, are the most insidious and deadly side effects of the drug.

"There have been steady increases in the number of deaths due to cocaine," said Adams of the drug abuse institute. "Perfectly healthy young people, with no other risk factors like being overweight, have died of heart attacks after snorting cocaine."

Officials in Maryland have attributed Bias' death to cardiac arrest, and Prince George's County police are analyzing white powder found in his leased sports car.

In 1981, three cocaine-related deaths were reported in the District. Last year, there were 88, including four suicides, according to D.C. police.

Despite the immediate risks of cocaine use, and possible long-term effects such as sleeplessness, irritability, impotence and paranoia, the drug retains a powerful allure. Users say it produces an intense feeling of pleasure, particularly the first time around, and a sense of energy and euphoria.

What follows that initial high is what some addicts call "the cocaine crash," a strongly experienced feeling of helplessness and overwhelming desire to re-create the drug high.

In testimony before the President's Commission on Organized Crime in 1984, Karyn Richwein, a recovering drug addict from Howard County, said: "The high I felt when I was on cocaine was so much greater than anything else I had ever experienced before.

"Everything I saw was brighter," said Richwein, then 20 years old. "I felt a lot happier. Every time I would ever do another drug, it was always to feel that way again."

A 29-year-old Montgomery County woman, who asked not to be identified by name, said her nearly 10-year cocaine addiction led her to steal tens of thousands of dollars from two employers, a marketing firm in Rockville and an architectural design company in Bethesda, to support her habit.

By last summer, her habit of snorting cocaine had created a hole the size of a quarter in her septum, the cartilage that divides the nose, she said. After reconstructive surgery, she switched to freebasing, the process of smoking a concentrated form of cocaine.

"It's so ironic about this drug," the woman said yesterday, six months after checking herself into a hospital to rid herself of the habit. "The drug makes you feel so good, so in control, but I reached a point where I was miserable almost every minute I was awake. I got to the point where I didn't want to live any more."

As with other cocaine users, it was relatively simple for the Montgomery County woman and Richwein to obtain the drug in their respective communities. The woman depended merely on a couple of close friends, one of them her boss, to supply cocaine, she said.

Richwein testified that she obtained cocaine and other drugs mostly "from friends in school."

Local police say the dozens of bars and gathering places that dot the suburban landscape are also relatively discreet, convenient places to buy and sell cocaine. "You can get it at any large nightclub in this county," said Prince George's County police Sgt. Gerry Speck, head of one of the county's two narcotics teams.

"It's ludicrously easy -- ask the bartenders, the waitresses," Speck said. "See the man who the girls are flocking around. That's where the cocaine is."

By contrast, buying cocaine in the District can be a ride on the wild side. The city's street markets are generally in tough areas of town where shootings, robberies and even murders have occurred when a customer or seller felt that a deal went bad.

At most of the estimated 17 cocaine street markets in Washington, a youthful entrepreneur quickly appears at buyers' car windows asking, "Whatcha need?"

A "small hit," enough for one snort of cocaine, costs $15 and usually comes wrapped in notebook paper or tinfoil.

But the usual sale is for a "half," a half-gram of cocaine, which costs $50. A full gram, called a "whole," sells for $100. Both amounts are sold in small plastic bags.

According to Capt. James Nestor, who heads the police department's narcotics branch, the "small hit" is a fairly new packaging ploy in the local cocaine market, and its low price has created new groups of buyers -- blue-collar workers and teen-agers.

For the middle-income buyer who may want to buy an ounce at a time for an average of $2,000, dealers will arrange home or office delivery, according to Nestor. Contact is made through electronic pagers, saving well-heeled buyers a drive through unfriendly neighborhoods.

Area police departments, already overwhelmed by a spiraling trade in cocaine and other drugs, are anticipating an influx this summer of the more potent and addictive form of cocaine called "crack."

Crack, which is sold in tiny pellets of nearly pure cocaine, has emerged in recent months in New York, Detroit and Los Angeles. Crack is not diluted by the additives customarily found in cocaine sold here, and is smoked rather than sniffed, producing a more intense but shorter-lived high.

On June 1, Montgomery County police raided a Gaithersburg hotel and seized approximately two pounds of cocaine, including some crack, according to police and county government sources. In Prince George's, Speck said, police seized some crack within the past week, but he added that "it wasn't an appreciable amount."

In the District, police believe that a substance recently recovered in two raids and resembling "old Ivory soap chips" will prove to be crack.

Regardless of whether crack inundates the area this year, authorities contend that they will have a hard time controlling the spread of cocaine and mobilizing public opposition to the popular drug.

"Our only hope is that people will come out from the fog," said O'Leary of the DEA. "Our job is to hold the line for a while until the reinforcements come. The reinforcements are the public."

Staff writers Donald P. Baker, Patricia Davis, Jeffrey Goldberg, Anndee Hochman, Bridgette Lacy, Courtland Milloy, Nancy Scannell and Michael Specter contributed to this report.