Vitiation of agni in Amashaya (stomach) region due to various causes Amlapitta. Some of the common causes are - fasting, eating between meals, 
worry, hurry, spicy foods etc. are some pitta vitiating factors etc. These factors derange the pachaka pitta (digestive enzymes etc.) and as a result pachaka pitta vitiates. 
Thus developed condition is called Amlapitta.
Hydrochloric acid (HCl) when not utilized well, or when produced in large quantity in the stomach region causes inflammation of stomach (gastric = related to stomach), 
that is called gastritis. This can derange the digestive procedures. The increased or normal level of HCl can destroy the soft tissue (epithelium) lining of oesophagus, 
stomach,duodenum etc. If not managed on time this can give rise to ulceration (breech in tissue).
Usually the esophageal sphincter muscle contracts thus preventing the stomach acid from shooting  up into the esophagus, but if this muscle is not functioning properly, the acid can slip past it and this is when heartburn symptoms start, which is called Gastroesophageal reflux.
Classification:
    •    Adhoga Amlapitta (downward)
    •    Urdhwaga Amlapitta (upward)
    •    Vata predominant Amlapitt 
    •    Pitta predominant Amlapitta
    •    Kapha predominant Amlapitta