Usually when an elderly person falls its either because they slipped on something or because they might have had a stroke..my grandmother years ago had fallen in her room, appeared fine, a year later when she had to go to the hospital for other issues the doctor told my Mom “Did you know she had a stroke” it must have been a minor one because she showed no ill effects from it..depends on the severity of the stroke
Early one morning, I drove over to check on Daddy. He was 88 at the time and I found him on the carpet. He said he was checking the carpet for something but it was obvious he had fallen and had been lying there all night.
The paramedics did a fine job of getting him to the hospital without any more damage. They took some X-Rays and the Dr. at the emergency room did not think he had broken anything but when the radiologist arrived, he said his hip was broken in 4 places. They operated, put 4 pins in and the hip healed just fine but Daddy never walked again.
He made it to 90 in a nursing home but he was never the same physically or for that matter, mentally.
True, lots of possible reasons...so sad when it happens.