Newswise — More than 1.2 million Americans " roughly equivalent to the population of Dallas " were hospitalized for pneumonia in 2006, making this lung infection the most common reason for admission to the hospital other than for childbirth, according to the latest News and Numbers from the Agency for Healthcare Research and Quality.

Treating pneumonia cost hospitals $10 billion in 2006. The disease, which can be especially deadly among the elderly, occurs when the lungs fill with fluid from infection or inflammation caused by bacteria or a virus.

AHRQ's new analysis of 2006 hospitalizations estimated admissions and hospitals' costs for other common conditions:

Hardening of the arteries: 1,198,000/$17 billionCongestive heart failure: 1,099,000/$11 billionChest pain: 857,000/$4 billionInjuries to the mother during birth: 818,000/$2 billionOther complications of labor and delivery: 767,000/$3 billionHeart rhythm problems: 749,000/$7 billionOsteoarthritis: 735,000/$10 billionHeart attack: 675,000/$12 billion

This AHRQ News and Numbers is based on 2006 data in HCUPnet (http://hcupnet.ahrq.gov/), AHRQ's free, on-line query system based on data from the Healthcare Cost and Utilization Project. HCUPnet provides reporters and others fast and easy access to health statistics on hospital inpatient and emergency department utilization.