About 90 percent of soldiers from the Nepalese Army were sent to the stricken areas in the aftermath of the earthquake under Operation Sankat Mochan, with volunteers mobilized from other parts of the country.[117] Rainfall and aftershocks were factors complicating the rescue efforts, with potential secondary effects like additional landslides and further building collapses being concerns. Impassable roads and damaged communications infrastructure posed substantial challenges to rescue efforts.[118] Survivors were found up to a week after the earthquake.[119][120][121]
As of 1 May 2015, international aid agencies like Médecins Sans Frontières (Doctors Without Borders) and the Red Cross were able to start medically evacuating the critically wounded by helicopter from outlying areas, initially cut-off from the capital city, Kathmandu,[17] and treating others in mobile and makeshift facilities.[122][123] There was concern about epidemics due to the shortage of clean water, the makeshift nature of living conditions and the lack of toilets.