Which cities are worst for asthma sufferers?
Health group ranks 100 metro areas
Knoxville, Tennessee, tops the Allergy and Asthma Foundation of America's list of the 100 worst places for asthmatics. CNN's Holly Firfer reports.
According to a new survey, these were the worst places for people with asthma:
1. Knoxville, Tennessee
2. Little Rock, Arkansas
3. St. Louis, Missouri
4. Madison, Wisconsin
5. Louisville, Kentucky
6. Memphis, Tennessee
7. Toledo, Ohio
8. Kansas City, Missouri
9. Nashville, Tennessee
10. Hartford, Connecticut
(CNN) -- Asthma hits all areas of the United States, but Knoxville, Tennessee, is the worst, according to an organization's ranking of the nation's cities released Tuesday.
Tennessee is also home to two other cities in the top 10: Memphis and Nashville.
To bring awareness to the potentially fatal disease, the Allergy and Asthma Foundation of America developed a list of 100 metropolitan areas across the country that they term "asthma capitals."
The group looked at the prevalence and mortality from the disease, outdoor air quality, smoking laws and the number of asthma medication prescriptions and specialists.
While Knoxville takes the top spot, Arkansas' capital, Little Rock, and St. Louis, Missouri, follow as the most challenging places for asthmatics to live, according to the AAFA ranking. Madison, Wisconsin, and Louisville, Kentucky, come in at fourth and fifth, respectively.
The remaining top "asthma capitals" are Memphis, Tennessee; Toledo, Ohio; Kansas City, Missouri; Nashville, Tennessee; and Hartford, Connecticut.
"[The list] gives us evidence of how prevalent asthma is across the country -- a disease that has increased two-fold in the past two decades," said Dr. Derek Johnson of Temple University Children's Medical Center and member of the group who released the city rankings.
Government figures show asthma affects more than 20 million people in the United States and accounts for nearly 5,000 deaths each year.
The most common form of asthma is allergic asthma, triggered by exposure to such things as pollen, mold, weather changes and viral or sinus infections.
Like many with allergic asthma, Nancy Hammonds is keenly aware spring is in the air as coughing and sneezing are beginning to control her life.
"The allergies make me feel really heavy in the chest," she explained. "I wheeze, get up sometimes in the night coughing."
These allergies sometimes aggravate her asthma to the point where she can't talk or get enough air into her lungs.
Doctors warn that just because you have allergies, you won't necessarily develop asthma. But Hammonds, who has had the disease for more than 40 years, said controlling the symptoms for her is crucial to stay alive.
"Sometimes you feel close to death if you don't breathe very well," she said. "It is terrifying sometimes."
The AAFA said its "asthma capitals" list is meant to help people recognize symptoms and causes of asthma, especially those living in the cities where asthma is most prevalent.