The most difficult and painful days following shoulder replacement surgery typically occur between day two and day five post-operation. During this window, the initial long-acting regional nerve block wears off completely, acute surgical inflammation peaks, and post-operative stiffness sets in. Patients frequently report that managing breakthrough pain, dealing with severe sleep deprivation caused by sleeping upright in a sling, and navigating the initial transition to unassisted movement represent the most grueling phase of early recovery.