Staying home with the flu can be hard for workers, but it’s better for you and others.

Rachel Figueroa-Levin, 26, doesn’t work outside her New York home and yet she’s worried that the nasty flu circulating in the city’s workplaces is going to make it through her doors, to her 2-year-old daughter, via her office-worker husband.

If it does, she’s going to be angry. “If my husband comes home from work sick, I’m going to try to figure out which co-worker infected him and think nasty things about them,” says Figueroa-Levin, a blogger and soap maker.

She has a point. Health experts agree that if you have the flu, you should stay away from work until you are better.

But that can be tough, especially for the 40% of workers in the private sector who don’t have paid sick leave, according to the Institute for Women’s Policy Research . In the 2009 flu epidemic, 8 million out of 26 million stricken adults took no time off, a study by the institute found. Result: They passed the flu to 7 million of their co-workers and to unknown numbers of friends, family members and strangers, the study found.

“We know that many people are under pressure to go to work,” says Andrew Pavia, chief of pediatric infectious diseases at the University of Utah and an influenza adviser for the Infectious Disease Society of America.

Yet Pavia and other experts say there are many good reasons to resist that pressure during this winter’s widespread flu epidemic (even if you don’t work with Rachel Figueroa-Levin’s husband). Here are a few:

• You feel awful. The flu is not a cold. “The typical case of the flu starts suddenly, and you feel like you were hit by a truck,” Pavia says. For adults, he says, the flu often feels “like the worst viral illness you’ve had in 10 years.”

The flu comes with fever, aches, cough, tiredness and sudden onset — which you can abbreviate and remember as FACTS, says Susan Rehm, an infectious disease specialist at Cleveland Clinic and medical director of the National Foundation for Infectious Diseases.

Most people with the flu are just too sick to work effectively, Pavia adds. “Many people will find they get more work done by going home and recovering than by going in and walking around like a zombie.”

• You may get better sooner. “For most infectious diseases, rest seems to speed recovery,” Pavia says. “Sometimes your mother was right.”

Rehm agrees: “It takes a lot of energy to fight an infection, and resting is one of the ways you can conserve that energy.”

Staying home also may give you time to call your doctor in the first day or two of your illness to find out if it makes sense for you to try Tamiflu or Relenza, antiviral medicines that can shorten the duration of flu, according the Centers for Disease Control and Prevention.

• You will protect others. There’s no easy formula to predict how many other people a sick worker may infect, Pavia says. Outdoor construction workers may share fewer bugs than cramped office mates. Those who work with the public may spread around more flu than those who don’t.

But you don’t need to touch or breathe on someone to infect them. Coughs and sneezes can spread viruses to people 6 feet away, Pavia says. Some viruses stay suspended in the air and travel even greater distances, he adds. Flu viruses also can survive on surfaces — such as keyboards, desks and doorknobs — for up to 24 hours and infect people who touch them and then touch their eyes, noses and mouths, says Neil Schachter, medical director of respiratory care at Mount Sinai Medical Center, New York.

As a general rule, you will be most infectious when you first get sick and OK to return to work 24 hours after your fever breaks — a signal that your immune system has the upper hand, Schachter says. Some people with relatively mild cases will reach that milestone in a couple of days, but others will need several days, he says.

• It might be a matter of life and death. The flu is a passing illness for most of us, but a killer for a few. You don’t have to work in a nursing home, hospital or preschool to worry about whether someone in your workplace might be at high risk. “Really think about who you work with,” Pavia says. People with cancer, heart and lung disease and women in late pregnancy are at increased risk for flu complications, he says.

So is anyone over age 65, and “we don’t all retire at 65 anymore,” Schachter says.

Your high-risk co-workers also give you good reasons to get a flu vaccine, experts say, this year and every year.

• It’s also polite. Maybe you would never go to work with the flu, because, at the very least, it’s rude.

But is it OK to become the etiquette police when you catch a co-worker red-nosed and feverish during a flu epidemic? There’s no need for that, says manners maven Anna Post, of the Emily Post Institute. “You can simply say, ‘Hey, Tom, you don’t look so good, maybe you should go see your doctor.’ That makes it about their well-being,” she says.

Post also has a suggestion for bosses who don’t want the flu spreading through their troops: Be the first to give in and go home if you are sick.

“You can set the tone. Say, ‘I’ve got the flu, so I’ll be out for the next several days. I’ll check in when I can.’ ”