Flu season has arrived, and many people are lining up for flu shots, if they haven't gotten one already.

Health experts say children who have chronic conditions -- such as heart disease, asthma and other lung problems -- should get the flu vaccine each year. And a new study shows why children with conditions such as cerebral palsy and muscular dystrophy have recently been added to that list.

Kyrra, 6, has asthma. Since asthma is on the list of chronic conditions that put kids at risk for serious complications from the flu, Kyrra got a flu shot.

Debrianna, 3, has a different kind of chronic condition. She has a neuromuscular disorder that makes some of her muscles unusually weak.

A new study shows why doctors now recommend that children who have neurological or neuromuscular diseases get the flu vaccine.

"Neurological diseases include diseases like cerebral palsy and seizure disorders," said Dr. Ron Keren, with Children's Hospital of Philadelphia. "Neuromuscular diseases include conditions like muscular dystrophy or spinal muscular atrophy."

The study, published in Wednesday's issue of the Journal of the American Medical Association, focused on children already hospitalized with the flu.

Researchers at several institutions across the country conducted the U.S. Centers for Disease Control and Prevention study.

They studied the health records of more than 700 children hospitalized with the flu between the years 2000 and 2004. They found that those with neurological or neuromuscular disease were more likely to have the most dangerous breathing problems, even compared to children with asthma or lung disease.

Keren said children who were hospitalized with flu who have heart disease, lung disease or neurological and neuromuscular disease have about a 10 percent chance of developing breathing problems that would require the need for a breathing machine.

"The presence of two of these conditions actually increased the risk of developing breathing problems that would require the need for a breathing machine to 30 to 40 percent," Keren said in a news release.

When it comes to flu shots, Keren said kids with neurological and neuromuscular disease shouldn't have priority over children with other chronic medical conditions. But they should receive the vaccine, just like children with heart disease, lung disease, diabetes or sickle cell disease.

Talk with your pediatrician to find out if your child should receive an annual flu shot.