Tracie Kolar contends that she is entitled to Social Security disability benefits as a re- sult of pain from fibromyalgia. An Administrative Law Judge concluded, after a hear- ing, that although her condition is serious her pain is not so great as to preclude all sed- entary employment—and that Kolar, who has two years of college education and a work history of responsible sedentary jobs, could find suitable work. In this suit seeking judicial review of that decision, the parties agreed to have the dispute resolved by a magistrate judge. 28 U.S.C. §636(c). The magistrate judge ruled that the ALJ’s decision is supported by substantial evidence. 2016 U.S. Dist. L EXIS 12362 (N.D. Ill. Feb. 2, 2016). *2 No. 16-1723 Page 2

The theme of Kolar’s appellate brief is summed up in its argument headings: Kolar contends that the ALJ “failed to properly evaluate the treatment notes” of one physi- cian, “erred in discrediting the opinion” of another, and “erred in evaluating the plain- tiff’s subjective allegations”. But we do not review the decision of an ALJ as if it were the opinion of a district court on summary judgment. The question instead is whether substantial evidence supports the ALJ’s ultimate decision—that Kolar’s pain is mild enough to enable her to work, as millions of other persons with chronic pain do. ALJs need not comment on every line of every physician’s treatment notes, as Kolar’s lawyer supposes; it is enough to recognize and respond to the physician’s principal conclu- sions, which the ALJ did.

The conclusion that the ALJ “discredited” is a statement by one physician that Kolar is unable to engage in gainful employment. That’s not a medical conclusion at all. Phy- sicians determine a claimant’s symptoms and causes, but the ALJ, here with the aid of a vocational expert, decides whether work is available for someone with those conditions.

Her ability to work depends on just how much chronic pain she suffers from. Since pain is subjective and affects people in different ways, it is difficult to determine how much pain is present and how great its effects are. Fibromyalgia can have a wide range of effects. Almost any conclusion an ALJ reaches in such situations may be inconsistent with some evidence in the record and consistent with other evidence. This is where the substantial-evidence standard of review matters. Like the district court, we conclude that substantial evidence supports the ALJ’s decision.

The magistrate judge wrote a careful opinion summarizing the arguments and con- clusions. We substantially agree with that analysis.

A FFIRMED