Is a prison official liable for deliberate indifference to serious medical needs?

indifference to serious medical needs." Estelle v. Gamble, 429 U.S. 97, 106 (1976). To act with deliberate indifference, a prison official must both be aware of facts from which the inference could be drawn that a substantial risk of serious harm exists, and he must also draw the inference. Farmer v. Brennan, 511 U.S. 825, 837 (1994). Thus, a defendant is liable if he knows that plaintiff faces "a substantial risk of serious harm and disregards that risk by failing to take reasonable measures to abate it." Id. at 847. "[I]t is enough that the official acted or failed to act despite his knowledge of a substantial risk of serious harm." Id. at 842.