Feels like a semi truck is sitting on my chest

[ciqala]

My heart feels like a nut cracker is clenching it. My chest feels like it is going to collapse. The suffocating feeling is so strong. My arms go numb, feels like a lot of pressure. Sometimes sharp pains in my chest.

*I can breathe fine. Sure breaths put more pressure on my heart, but it is not asthma.
* I am young, 21 years old.
* I am extremely fit and physically active. You could say I might overwork myself. Avid athlete.
* This usually happens during cardio, but never when I am tired. It is random. Has nothing to do with my body feeling exhausted. Sometimes happens when i am dormant.
* Happens a lot when I play sports, when I have adrenalin and non stop energy going on.  
* My heart feels heavy when I am under water, for example in the bathtub.
*It eventually calms down and goes away. I have not almost died yet from it so haven't gone to hospital to get checked.

*My pulse rate skyrockets triple times the count it should be, sometimes it feels like it skips beats.
  
What the hell is this? Does this happen to other athletes? It always feels like i'm about to have a heart attack.
  

[ciqala]

thanks for the concern.
I posted this awhile ago.
This whole thing is still unresolved. I went in for a bunch of tests. Had the heart monitor on, for a 24 hour period where i was to try and induce the symptoms. I only suceeded in rising my pulse to extremes. The results came back perfectly fine. Nothing wrong with my heart beats at all.
Today I got the results.

My doctor told me it could be panic attacks. Do I beleive this? Not really, i'm still worried, but he seems to not want to continue figuring anything out.

I have had a past of panic attacks and i know how real they can feel. But NEVER before have they made me feel truly significantly in physical danger.

This one time a strange episode made my completely deaf for a few minutes, i felt like i was having a heart attack, and i was about to faint. it went away after an hour, and after i was able to eat something. but everytime i stood it just got worse. i was paralysed in spot, not able to make a movement. THat was not a panic attack. That was an actual fainting spell. I know that because i've fainted before. The horrible ringing in your ears... well this time i heard a pop, and then couldn't hear anything for awhile. i thought my head would literally explode.
He said that adrenalin and getting my pulse rate up could induce panic attacks.
And also it is fairly common for young women between the ages of 16 and 25 to have
similar symptoms of low blood pressure, fast pulse, and fainting episodes. not as extreme i would think.
My blood pressure is also very low, but everything else from blood tests came back fine.
But these symptoms feel more than something mental.
I guess everything entwined, with me doing too much physical activity could result in all of this... I don't know!

[mysolution]

Please go to the emergency room immediately. Have someone drive you. I'm not a doctor, but I feel any responsible physician would advise you to get immediate and thorough diagnosis of these very serious symptoms.  

[whisperwolf]

Go see your doctor!  

It could be a lot of things, from anxiety, to hypertension, to asthma to a heart condition.  None of which I would want to guess about or ignore.