<s>[INST]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?[/INST]Hi, It Could be because of bronchitis(allergic 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,</s>