<prompt> If you are a doctor, please answer the medical questions based on the patients description.im 15 years old. ive had mono about three years ago and sometimes i feel like the symptoms come back. i feel tierd but idk if its just because its summer but persistant symptoms are when i stand up to quick or after siting or a long time i start to blackout, feel my chest tightening and feel like i cannot breathe for 2-5 seconds depending how bad the tightening feeling gets. sometimes i also feel a little dizzy but that comes and go with my tiredness. any ideas?  <response>: Hi, It Could be because of bronchitisallergic or infective or pertussis or seasonal asthma etc. You may undergo routine blood count, ESR with X-ray chest and pulmonary function test. You might require antibiotics quinolones or accolades or amoxicillin with clavulanic acid with cough suppressants antiallergic antihistamines or mast cell stabilizers and anti-inflammatories or analgesics on as and when required basis. You must consult your pulmonologist to get diagnosed first and then seek for treatment. Thanks and Regards, 