H1N1 Flu Virus (Swine Flu)

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 protection is to get a flu vaccine, or flu shot, every year. Swine flu is one of the viruses included in the vaccine.

Slideshow: Is It a Cold or Is It the Flu?

Causes of Swine Flu

Swine flu is contagious, and it spreads in 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 or touch a surface (such as a doorknob or sink) that an infected person has recently touched, you can catch H1N1 swine flu.

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

Swine Flu Symptoms

People who have swine flu can be contagious 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.

Most symptoms are the same as seasonal flu. They can include:

• cough
• fever
• sore throat
• stuffy or runny nose
• body aches
• headache
• chills
• fatigue

Like seasonal flu, swine flu can lead to more serious complications, including pneumonia and respiratory failure. And it can make conditions like diabetes or asthma worse. If you have symptoms like shortness of breath, severe vomiting, abdominal pain, dizziness, or confusion, call your doctor or 911 right away.

Tests for Swine Flu

It's hard to tell whether you have swine flu or seasonal flu, because most symptoms are the same. People with swine flu may be more likely to feel nauseous and throw up than people who have seasonal flu. But a lab test is the only way to know for sure. Even a rapid flu test you can get in your doctor's office won't tell you for sure.