19 year old left side chest small aching pain lasts less than a minute, worse when i breathe in, approx 3 times a day. what could it be? stress?

Chest pain concerns : Most chest pains in healthy children and young adults are non-cardiac in origin. They are mostly muscular in nature or due to other inflammation of the rib cage. Occasionally temporary thickening of lining over lung or a small pocket of air can cause chest pain when breathing in. If pain recurs, worsens or u develop additional symptoms such as fever, difficulty in breathing, get yourself checked.