I had this symptom for a long time (and still have it to an extent). It felt like the same blood pressure problem when I exercised, and when I sang (I was an amateur opera singer and so sing in a very 'physical' way, right from the diaphragm etc.)

I tested it a fair bit as I found giving up my singing very difficult, and never did it 'blow' - I think it is just very uncomfortable but I wouldn't expect it to cause any long term damage from some major catastrophic event.

In the meantime just get used to bending at the knee instead of the waist to pick things up off the fllor. It will be better for your lower back too! This symptom should pass eventually.