The difference between acute, subacute, or chronic is a matter of time. Different sources name the time frame differently. The cut off point seems to be somewhat arbitrary.
According to a recent study of back pain progression, the first two weeks after injury or start of symptoms is the acute phase. Pain past 14 days is labeled subacute. It’s generally agreed that pain persisting past three months is becoming chronic.
With chronic pain comes loss of function, disability, and decreased quality of life. Treatment during the chronic phase is focused on preventing disability. A pain center can help address all of your needs, not just the back pain itself.
This type of treatment is a good idea for anyone with chronic pain. The earlier the intervention, the greater your chances for improved function and even recovery.