Chest pain, high blood pressure, heart issues... help?

I've been dealing with some chest pain for about two weeks now. It’s located near my left arm. About a month ago, I had these pulsating pains in the upper left side of my chest, and now they've returned. Last night, my heart was pounding so hard it felt like it was shaking me, which makes sleeping pretty uncomfortable. I did get an EKG done a month ago, and everything seemed fine at the time.
I checked my blood pressure today, and it stayed around 145/90 almost all day. That seems a little high, I guess.
I have a doctor's appointment tomorrow. I plan on carrying weights and using my stationary bike all day to prepare.

What could this be? Maybe nerve issues? Or an arrhythmia?

I don't really think it's an arrhythmia. People usually say an arrhythmia feels like your heart is "skipping a beat," but that isn't what I feel. It just pounds heavily during the night. It might happen during the day too, though I might not notice since I'm active constantly. I stay moving from morning until night, so I get pretty exhausted. I'm at work by 8:00 AM, walking the dog at 3:00 PM, and then I'm out doing things again at 6:00 PM until maybe 8:00 or 9:00 PM. This is my daily routine.

Look, man, there’s really nothing else anyone can tell you until you go get some more intensive diagnostic testing done. It could be anything from heart issues—like angina, cardiomyopathy, a weirdly placed aneurysm, or valve problems—to lung stuff like atypical pneumonia or pleurisy, maybe even hyperthyroidism, or honestly, most likely just a whole lot of nothing.

You'll probably end up going through the ringer with things like expanded blood work, another EKG, stress tests, a Holter monitor, standard chest X-rays, maybe an echocardiogram, or thyroid hormone panels... that's the general gist, and if they catch something specific, then they'll start digging deeper in that direction.

But more often than not, you’ll find yourself getting scanned from head to toe only for them to come back with nothing, the whole thing passes, and you never have to deal with it again.

Still, you've just gotta put in the effort and have some patience while you navigate all these tests. Just make sure you land in the hands of a doctor who actually knows what they're doing instead of some amateur who'll just run you around in circles until you're exhausted—it's a real pain.

Good luck 👋

Ugh, so I ended up in the ER last night because my heart was absolutely racing out of my chest! For hours on end, my pulse just wouldn't drop below 180, and when they checked me at the hospital, they actually clocked it at 206!
They ran some blood work right away which came back totally fine, and my EKG showed a normal sinus rhythm, just... you know, insanely fast.
Now I’m stuck waiting on thyroid hormone tests, seeing a cardiologist, and getting an ultrasound scheduled.
But honestly, after those intense few hours, my heart rate just decided to chill out and go back to normal all by itself, and I've been feeling totally fine since!