Approximately one-quarter of American adults have been diagnosed with arthritis and another 17 percent may be suffering from the crippling disease, the Centers for Disease Control and Prevention said.

Arthritis, a musculoskeletal disease that causes painful inflammation in the joints, is the leading cause of disability in the United States and a major financial drain on the nation’s health care system.

The percentage of those diagnosed with a form of arthritis, rheumatoid arthritis, gout, lupus or fibromyalgia ranged from a low of 17.8 percent in Hawaii to a high of 35.8 percent in Alabama in 2002, according to a 30-state CDC survey released Thursday.

The median rate was 27.6 percent.

“That is a huge number compared to most other diseases,” said Dr. Chad Helmick, a CDC arthritis expert, who noted that the number of Americans with arthritis was expected to increase sharply as the baby boomer generation headed into retirement.

The CDC also found that about 20 percent of respondents in a number of states in the survey had chronic joint pain, aching or stiffness indicating possible arthritis that had not been diagnosed.

Besides causing untold human suffering, the disease is also exacting a heavy financial toll.

The estimated direct and indirect costs of arthritis and other related rheumatic diseases was $86.2 million in 1997, equivalent to about 1 percent of the nation’s gross domestic product, the CDC said in a separate study.

Americans spent $51.1 billion on medical treatment for arthritis and related diseases in 1997, while lost earnings due to hospitalization, illness and disability added up to $35.1 billion.

Health experts believe that a combination of proper diet, weight control, exercise and regular medical treatment are effective in controlling both the prevalence and severity of arthritis.