H1N1 Flu Virus (Swine Flu)

Medically Reviewed by Carmelita Swiner, MD on May 16, 2023
4 min read

H1N1 flu is also known as swine flu. It's called swine flu because in the past, the people who caught it had direct contact with pigs. That changed several years ago, when a new virus emerged that spread among people who hadn't been near pigs.

In 2009, H1N1 was spreading fast around the world, so the World Health Organization called it a pandemic. Since then, people have continued to get sick from swine flu, but not as many.

While swine flu isn't as scary as it seemed a few years ago, it's still important to protect yourself from getting it. Like seasonal flu, it can cause more serious health problems for some people. The best bet is to get a flu vaccine, or flu shot, every year. Swine flu is one of the viruses included in the vaccine.

The same way as the seasonal flu. When people who have it cough or sneeze, they spray tiny drops of the virus into the air. If you come in contact with these drops, touch a surface (like a doorknob or sink) where the drops landed, or touch something an infected person has recently touched, you can catch H1N1 swine flu.

People who have it can spread it one day before they have any symptoms and as many as 7 days after they get sick. Kids can be contagious for as long as 10 days.

Despite the name, you can't catch swine flu from eating bacon, ham, or any other pork product.

These, too, are pretty much the same as seasonal flu. They can include:

Like the regular flu, swine flu can lead to more serious problems including pneumonia, a lung infection, and other breathing problems. And it can make an illness like diabetes or asthma worse. If you have symptoms like shortness of breath, severe vomiting, pain in your belly or sides, dizziness, or confusion, call your doctor or 911 right away.

Yes. Without one it's hard to tell whether you have swine flu or seasonal flu, because most symptoms are the same. If you have swine flu, you may be more likely to feel sick and your stomach and throw up than with regular flu. But a lab test is the only way to know. Even a rapid flu test you can get in your doctor's office won't tell you for sure.

To test for swine flu, your doctor runs a swab -- a bigger version of the ones in your bathroom -- up the inside of your nose around the back of your throat. But the test isn’t as common or widespread as those for regular flu. So the only people who really need to be tested are those in the hospital or those at high risk for life-threatening problems from swine flu, such as:

  • Children under 5 years old
  • People 65 or older
  • Children and teens (under age 18) who are getting long-term aspirin therapy and who might be at risk for Reye's syndrome after being infected with swine flu. Reye's syndrome is a life-threatening illness linked to aspirin use in children.
  • Pregnant women
  • Adults and children with chronic lung, heart, liver, blood, nervous system, neuromuscular, or metabolic problems
  • Adults and children who have weakened immune systems (including those who take medications to suppress their immune systems or who have HIV)
  • People in nursing homes and other long-term care facilities

Some of the same antiviral drugs that are used to treat seasonal flu also work against H1N1 swine flu. Oseltamivir (Tamiflu), peramivir (Rapivab), and zanamivir (Relenza) seem to work best, although some kinds of swine flu don’t respond to oseltamivir.

These drugs can help you get well faster. They can also make you feel better. They work best when you take them within 48 hours of the first flu symptoms, but they can help even if you get them later on.

Antibiotics won't do anything for you. That’s because flu is caused by a virus, not bacteria.

Over-the-counter pain remedies and cold and flu medications can help relieve aches, pains, and fever. Don't give aspirin to children under age 18 because of the risk of Reye’s syndrome. Make sure that over-the-counter cold medications do not have aspirin before giving them to children.

The same flu vaccine that protects against seasonal flu also protects against the H1N1 swine flu strain. You can get it as a shot or as a nasal spray. Either way, it "teaches" your immune system to attack the real virus.

Besides a flu shot, there are other things you can do to stay healthy:

  • Wash your hands throughout the day with soap and water. Sing the "Happy Birthday" song twice to make sure you've washed long enough. Or use an alcohol-based hand sanitizer.
  • Don't touch your eyes, nose, or mouth.
  • Avoid people who are sick.