I have difficult to swallow saliva now i see little lump below adam apple which moves while drinking.i feel headache sometimes.what are its cause?

Male or Female??: I asked gender, because the male 'adam's apple" is routinely visible, but females generally do not have lumps or bumps in their neck. Bumps can be nodes, suggesting infection, abscesses, small benign tumors, thyroid growths or other rare diseases. Your endoscopy was(-)? See your primary care, and maybe an ENT (ear nose and throat) specialist. Don't put it off, because early rx is important!