Air embolism and veins is greater than atmospheric pressure, an air embolus does not often happen when a blood vessel is injured. In the veins above the heart, such as in the head and neck, the venous pressure may be less than atmospheric and an injury may let air in. This is one reason why surgeons must be particularly careful when operating on the brain, and why the head of the bed is tilted down when inserting or removing a central venous catheter from the jugular or subclavian veins. When air enters the veins, it travels to the right side of the
Head and neck cancer and Epstein-Barr virus. Head and neck cancers are most commonly of the squamous cell carcinoma type. The diagnosis is confirmed by tissue biopsy. The degree of spread may be determined by medical imaging and blood tests. Not using tobacco or alcohol can reduce the risk for head and neck cancer. While screening in the general population does not appear to be useful, screening high risk groups by examination of the throat might be useful. Head and neck cancer often is curable if it is diagnosed early; however, outcomes are typically poor if it is diagnosed late. Treatment may include a