Gastroesophageal reflux disease:
gastric reflux disease, or acid reflux disease is defined as chronic symptoms or mucosal damage produced by the abnormal reflux in the esophagus.
Hernia:
A hernia is protrusion of an organ or the muscular wall of an organ through the cavity that normally contains it. A hiatal hernia occurs when the stomach protrudes upwards into the mediastinum through the esophageal opening in the diaphragm.
Dental cavities:
also known as tooth decay or cavity, is a disease wherein bacterial processes damage hard tooth structure (enamel, dentin and cementum).[1] These tissues progressively break down, producing dental caries (cavities, holes in the teeth). Two groups of bacteria are responsible for initiating caries: Streptococcus mutans and Lactobacillus. If left untreated, the disease can lead to pain, tooth loss, infection, and, in severe cases, death.[2] Today, caries remains one of the most common diseases throughout the world. Cariology is the study of dental caries.
Achalasia:
Achalasia is characterized by difficulty swallowing, regurgitation, and sometimes chest pain. Diagnosis is reached with esophageal manometry and barium swallow X-ray studies. Various treatments are available, although none cure the condition completely. Certain medications or Botox may be used in some cases, but more permanent relief is brought by esophageal dilatation and surgical cleaving of the muscle (Heller myotomy).
Helicobacter pylori:
is a Gram-negative, microaerophilic bacterium that can inhabit various areas of the stomach and duodenum. It causes a chronic low-level inflammation of the stomach lining and is strongly linked to the development of duodenal and gastric ulcers and stomach cancer. Over 80% of individuals infected with the bacterium are asymptomatic.
Oral cancer:
Oral cavity cancer, a subtype of head and neck cancer, is any cancerous tissue growth located in the oral cavity.[1] It may arise as a primary lesion originating in any of the oral tissues, by metastasis from a distant site of origin, or by extension from a neighboring anatomic structure, such as the nasal cavity or the maxillary sinus. Oral cancers may originate in any of the tissues of the mouth, and may be of varied histologic types: teratoma, adenocarcinoma derived from a major or minor salivary gland, lymphoma from tonsillar or other lymphoid tissue, or melanoma from the pigment producing cells of the oral mucosa. Far and away the most common oral cancer is squamous cell carcinoma, originating in the tissues that line the mouth and lips. Oral or mouth cancer most commonly involves the tissue of the lips or the tongue. It may also occur on the floor of the mouth, cheek lining, gingiva (gums), or palate (roof of the mouth). Most oral cancers look very similar under the microscope and are called squamous cell carcinoma. These are malignant and tend to spread rapidly.
All of the conditions listed above are known to have a "bitter taste in your mouth" as a symptom.