Experiencing prolonged chest congestion. x-rays, blood tests negative. antibiotics didn't work. have been trying zyrtec at night, together with nasal spray qnasl (beclomethasone dipropinat) to reduce post-nasal drip. after one week, cough is less persiste

Bronchospasm ....: You may have some bronchospasm contributing to your symptoms. Perhaps a trial of a bronchodilator inhaler with a steroid inhaler would be worthwhile to see if the cough/congestion resolves further. You may have partial treatment with your current regimen. See your doctor to try this approach. If you smoke, you need to quit to decrease airway inflammation.

Right direction: Common causes of cough, other than infection are reflux and post-nasal drip. It sounds like the evaluation has looked for the more serious causes, but if the problem persists, continue to work with your doctor. Sometimes a pulmonary doctor can help with more resistant coughing.

Chest congestion: With what you describe it sounds like you may have allergic respiratory disease. This is a asthma like problem and if your zyrtec (cetirizine) is not doing the job see your doctor.