Is High Normal Range Carbon Dioxide Level A Matter Of Concern?

I DID NOT KNOW THT I HAD TO PAY TO OBTAIN AN ANSWER. I WILLCONSULT MY PRIMARY CARE PHYSICIAN, MONDAY. PLEASE DISEGARD MY Q. I have no current symptoms. However, routine blood work just returned last week, and my carbon dioxide / rating level was at the top of the scale - a 20 I believe. SHOULD I BE CONCERNED WITH THIS HIGH NORMAL RANGE CARBON DIOXIDE LEVEL? My doctor has said nothing about it. This is the third time in 2 years that it has been at the top of the normal range. Considering this...i overheated while working outside two years ago, did not have enough to eat or drink. After I returned home, it led to muscle spasms, which led to hyperventilation, which led - I believe - to hypoxia (tingling in my fingers and toes, spread to my hands and feet - continued into my lower legs and my arms. Also, tingling / numbness in my face as it progressed, until my hands cramped and crab clawed and I could not walk. ) My wife transported me to hospital and I was treated with IV fluids, breathing into bag and 02. In January 16, I had chest pains which led, I believe, to early onset of hyperventilation, as my finger tips began to tingle as my breathing rate increased and shallowed. I slowed down my breathing and the tingling disappeared. My wife xported me to hospital. The chest pains were related to strained muscle. I do not smoke, am 59yoa, former long distance runner, etc., etc. and in good health, but currently out of good conditioning. THANKS, Rory