Having sudden left side chest pains which last 10 seconds every hour-two hours, no other symptoms, angina? heart?

Chest pain: This chest pain described could be many things some minor and some potentially serious. At age 23 not really likely to be angina but I have seen teenagers have a heart attack. I recommend you call your physician or go to an ER. Chest pains needs physician evaluation.

Probably not: Probably not at your age. More likely to be something benign. Muscle pull, spasm, etc. Keep an eye on it thought.