Does sallowing saliva difficulty cause by nerve malfunction?i have right back head pain along with neck with swallowing problem.also belching problem.

I doubt it: If your tongue is straight, go see a gastroentrologist.

Dysphagia types: "transfer dysphagia" is a problem moving food/saliva from your mouth to the top of the esophagus; "transit dysphagia" is a problem transiting the food down the esophagus. Motility studies (modified barium swallow with speech therapist; esophageal manometry) may be helpful in identifying the point of pathology, if present. Sometimes, just esophageal spasms can make swallowing feel problematic.