**Endoscopy** is a medical procedure that examines the inside of the body using a narrow and flexible tube called an endoscope. This tool helps doctors to see different body parts such as stomach, intestines or lungs without the need for open surgery. Endoscopy is used to diagnose diseases, internal problems and perform special treatments such as sampling. This method is usually less painful and heals quickly. **How is endoscopy performed?** Endoscopy is a medical procedure that uses a thin and flexible tube called an endoscope to view the inside of the body. This tube has a camera and light and gives images of the inside of the body to the doctor. Endoscopy can be done through the mouth, nose, or a small incision, and is usually used to examine the stomach, intestines, or respiratory system. Depending on the type of endoscopy, local or general anesthesia may be used. Endoscopy and its types **Types of endoscopy** Colonoscopy (examination of the large intestine and prevention of colon cancer) . Bronchoscopy (viewing the lungs and respiratory tract) . Cystoscopy (bladder and urinary tract examination) Necessary preparation for endoscopy **How to prepare for endoscopy** In order to prepare for **endoscopy**, you should usually not eat anything for several hours before it. In some cases, your doctor may ask you to take medicines to clean your intestines or stomach. Also, you may need to stop certain medications a few days in advance. Be sure to consult your doctor about your health status and the medications you are taking so that you can be properly prepared. **Endoscopy applications** Endoscopy is used to diagnose and treat various body problems. It is used to check diseases such as stomach ulcers, intestinal inflammation and respiratory problems. It is also used in identifying cancers, especially digestive and lung cancers. In addition, endoscopy can be used to remove a sample (biopsy) or perform minimally invasive treatments such as removing polyps or stopping bleeding. When is an endoscopy necessary? Endoscopy is necessary when a person has problems such as stomach pain, prolonged indigestion, gastrointestinal bleeding or unexplained weight loss. Also, if there are symptoms of breathing or swallowing problems, endoscopy can be helpful. This method is also recommended for the diagnosis of gastrointestinal or lung cancers, and in some cases it is used to check infections or chronic diseases. Endoscopic considerations and complications **endoscopy complications** Endoscopy is usually safe, but complications such as mild pain or discomfort may occur in the examined area. Sometimes, minor bleeding from the sampling site or infection may occur. In rare cases, there is a possibility of damage to the internal tissues or perforation of the organ wall, which requires immediate treatment. These side effects are very rare and usually recover quickly after **endoscopy**. **Time to see a doctor** The time to see a doctor is when you experience symptoms such as persistent abdominal pain, intestinal bleeding, changes in bowel habits, or serious breathing problems. Also, if you have a family history of gastrointestinal diseases or cancer, it is better to visit a doctor periodically for examination. If abnormal symptoms persist, it is necessary to see a doctor. **Conclusion** Endoscopy is an effective and minimally invasive method for diagnosing and treating diseases. This method is very important in medicine with high accuracy, shorter recovery time and less risks. If you have suspicious symptoms or need periodic check-ups, seeing a doctor can help diagnose it faster and prevent serious problems.