Is pow(x,0.5) the same as sqrt(x) 
I think so. Then it is the resulting vector.
This offset seems very specific:
gForceX = (accelX-2050) / 16384.0;
gForceY = (accelY-77) / 16384.0;
gForceZ = (accelZ-1947) / 16384.0;
If the sensor is rotated a little, then the offset is wrong.
You could measure the increase/decrease of the resulting vector.
The MPU-6050 has an internal programmable 'dmp'. I think there is fall detection code for the 'dmp'. Some sensors have it already built-in.
I did not check the structure of the code. You can start by making the text of the code look better. Make consistent use of indents, put every comma, every space at the right place.
Have you investigated how the PulseOximeter library works ? That was an open end for me in your previous question. The library fails if it can not keep track of the heart beat.
The Blynk, SMS, and HTTP functions can take some time and there is a delay of 100ms. I can't tell how responsive the code is.
How serious is this project ? You should not use Arduino for life threatening situations.