Push Up

I haven't work out for more than a month, so last week I went back to the gym, met up with my PT and he decided to get a new regime for me.
Day 1, he made me do some weight training with dumbbells, chair dip, and the last one PUSH UP
I never did any push up before, as I believe I am not strong enough to do it. He encouraged me to do it. Well, apparently I was able to get 5 x 16 push up, which equal to 80.
I was super tired after the work-out; still managed to drive back home, but once I reached home I was wasted, I lied down and only managed to get up after 30 mins.
The next day, not so much pain yet, so I went to the gym again, didn't use much of arms, we did leg work out. Managed to finished all programs, tired but was still bearable compared to the arm day.
The days after were hell, arms super painful, and I started to have tingling sensation my my arms, sometimes I feel like I lost sense on them. I couldn't lift tea cups, I couldn't brush my teeth without having pain. Even hooking bra was a challenge. I couldn't sleep at night, and I end up taking painkillers. Thanks God for the painkillers.

Days after that, not much pain,  I still have sprain when I stretch (even until today). But 3 days ago (which is 1 week after the push up), I am not sure why my right arm began to swell. I bumped my right arm in the morning, yes, but it was a mild one, since I was wearing long sleeve, I didn't notice until I get changed at night. No pain, but my arms looks like a blown-up sausage. It is so fat that the skin gets tight and shiny. It feels firm and hard. And my right elbow loses its wrinkles, the swelling ruled out all the wrinkles. So scary.
I measured the circumference difference on left and right arms. The biggest difference was freaking 4 cm! Still swelling now, not sure when I will lose it. Hiks.

Notice that my right arm is much larger than my left one