Complications from standing near a blast (blast overpressure) include immediate or delayed injuries to gas-filled organs, such as ruptured eardrums, "blast lung" (pulmonary contusion/hemorrhage), and bowel perforations. Survivors may also experience traumatic brain injury (TBI), cognitive issues, severe headaches, and, from secondary fragments, penetrating injuries.

From what I gather off google

[–] KobaCumTribute@hexbear.net 19 points 23 hours ago

Even the mild concussion from being anywhere near an explosion also massively increases the rate of PTSD, too. Something about that kind of injury apparently sends the underlying mechanism that creates PTSD into overdrive, even in the absence of more direct trauma. It kind of makes sense it was originally named for that phenomenon ("shellshock") before it became understood that other things could also cause it, when this particularly sort of (comparatively mild) injury causes it at such a massively disproportionate rate that even the military couldn't deny that being on the receiving end of artillery fire was doing something even in the absence of visible injuries.