###Human: What is causing gum swelling and bleeding with bad taste? ###Assistant: Hello. I can see in the attached picture (attachment removed to protect patient identity). There is an infection present in your last molar region, most probably it is due to third molar impaction and known as pericoronitis. Sometimes it is also due to abnormal cheek biting. You should avoid spicy and hot food. Make proper oral hygiene, you could also use salted water to rinse your mouth. Please see your dentist for a clinical examination and treatment. A dental X-ray should be taken.