The pathophysiology of gastritis begins with the colonization of the stomach lining by Helicobacter pylori (H. pylori). This bacterium spreads mainly via the oral-oral route through saliva or shared utensils, and can also be transmitted in overcrowded or unhygienic environments through contaminated water, despite its brief survival outside the body.ColonizationOnce ingested, H. pylori enters the stomach and begins colonization by navigating through the mucus layer lining the stomach wall. It...

Helicobacter pylori, a resilient gram-negative bacterium, can thrive in the stomach's harsh, acidic environment. Infection with H. pylori leads to a cascade of events within the stomach lining. One of the critical disruptions caused by this bacterium is the interference with somatostatin production, a hormone responsible for regulating acid secretion. This interference tips the balance, escalating acid secretion and diminishing bicarbonate levels. This imbalance compromises the defensive...

Asthma is a chronic inflammatory disorder of the airways characterized by variable airflow obstruction and heightened bronchial responsiveness to a wide range of triggers. The underlying inflammation leads to airway swelling, mucus hypersecretion, and smooth muscle constriction, all of which narrow the airway lumen and impede airflow. Clinically, asthma presents with recurrent episodes of wheezing, shortness of breath, chest tightness, and coughing, symptoms that typically vary in intensity and...

Peptic ulcer disease develops when protective mechanisms of the gastrointestinal mucosa are overwhelmed by harmful factors, leading to localized erosions in the stomach or proximal duodenum. The main causes are Helicobacter pylori infection and chronic use of nonsteroidal anti-inflammatory drugs (NSAIDs).Helicobacter pylori–Induced InjuryBacterial Adaptation and Colonization:H. pylori is a spiral, Gram-negative bacterium adapted to the acidic stomach. and transmitted through oral-oral or...

Peptic Ulcer Disease (PUD) is characterized by the development of ulcers in the stomach or duodenal mucosa. Its pathophysiology is complex, involving a balance between damaging and protective elements.
Damaging agents such as Helicobacter pylori, gastric acid, pepsin, and nonsteroidal anti-inflammatory drugs (NSAIDs) can weaken the mucosal defense, allowing hydrogen ions to infiltrate back and harm epithelial cells.

Asthma is a chronic pulmonary condition involving inflammation of the airways, hyper-reactivity, and reversible obstruction of the airways. This condition can significantly impact a person's quality of life, making breathing difficult and leading to distressing symptoms.
Asthma is classified as allergic and non-allergic. Allergens such as dust mites, pollen, and pet dander trigger allergic asthma, while factors like cold air, intense emotions, or exercise can induce non-allergic asthma.