A nosocomial infection is an infection that a patient acquires while receiving treatment in a healthcare facility, such as a hospital or nursing home. These infections can occur due to various factors, including the use of invasive devices, surgical procedures, or the presence of other illnesses that weaken the immune system. Common types of nosocomial infections include surgical site infections, urinary tract infections, and pneumonia. They are often caused by bacteria, viruses, or fungi that are resistant to treatment, making them challenging to manage. Preventive measures, such as proper hand hygiene and sterilization of equipment, are essential to reduce the risk of these infections.