Sharp pain left side of chest

[saifn]

I accompanied my dad to a full cardio test at a leading centre recently, all the tests came out perfect but i was diagonized with high cholestrol(i want to ad i was on some sort of medication and was taking high cholestrol foods that time), i took medication and excersized well and this time my cholestrol is back to normal. My condition preceeds this test and i wanted to ask for a second opinion
     When i run on the thread mill i get sharp pain on the left side of my chest, soon as i stop it goes away, the pain does not come when i walk (including powerwalks) on the threadmill, it only happens when i run, what could be the problem? Am i breathing abnormally or is it something serious?
     Also recently i did started getting a funny muscle shivery feeling at the left side of my chest, there is no pain just a funny feeling that goes away after sometime.

I would also like to ad that i am 26 years old with no previous history of any abnormalities except the high cholestrol i was diagonized with which is now under control

[saifn]

After researching found out a cause, i would like to know if it could be

Precordial Catch Syndrome (PCS), also known as Texidor's twinge

[saifn]

I would also like to add that i get this sort of pain sometimes when i laugh hysterically, but only sometimes...really need to laugh my guts out for it :)