Hello, a few years ago i started feeling a sensation in my throat that doesn't go away if i swallow or cough. it gives me some dry cough and no sputum ever comes out. i did an endoscopy but nothing was detected, what could it be?

What type of scope was done? Did they look into your upper airway or your esophagus? If your upper airway was not scoped, you can see an ear, nose and throat doctor and they can use a small scope in the office to look into the upper airway while you are awake and you are having the symptom. If there is any abnormality in the upper airway, this will be seen. If nothing is seen, see a lung doctor.