My husband got a very sharp pain in his lower back, on the right side. it went on for a few minutes, he couldn't stand and we he sat down he struggles to get up because the pain is too much. is it serious? must i take him to the emergency rooms?

Muscle spasm: Sharp pain in the lower back is typically a muscle spasm. Apply alternating Ice and Heat for 10 min each, have him take some Ibuprofen every 6 hours, and have him lie flat on the couch or even the floor to give him support. Once he can move, have him do stretches as detailed at https://www.healthline.com/nutrition/stretches-for-lower-back-pain#1 for prevention and relief.