Proton Pump Inhibitors (PPIs) are a class of medications that reduce the production of stomach acid. They work by blocking the proton pump in the stomach lining, which is responsible for secreting acid. This helps treat conditions like gastroesophageal reflux disease (GERD), peptic ulcers, and Zollinger-Ellison syndrome. PPIs are typically taken orally and are available both over-the-counter and by prescription. Common examples include omeprazole, esomeprazole, and lansoprazole. While effective for many, long-term use may lead to side effects such as nutrient deficiencies and increased risk of certain infections. Always consult a healthcare provider for guidance.