The two most common types of tooth abscess are periapical abscess and periodontal abscess. A periapical abscess is commonly caused by a bacterial infection in the soft pulp of the tooth and is usually the result of a broken or cracked tooth, tooth decay, or extensive periodontal disease. An abscess will usually cause swelling and redness around the tooth and is accompanied by sharp, extreme, and throbbing pain. The painful area is usually localized to the impacted tooth and will be sensitive to touch, and can be aggravated by pressure and warmth. A bacterial infection causing the abscess will often cause a fever, which is a common and non-specific symptom seen in most viral, bacterial, or parasitic infections. A low-grade fever is a natural response that enhances the immune system to fight infection. Lymph nodes in the neck can also become swollen as a result of a tooth abscess, which is known as lymphadenopathy. Lymph nodes contain white blood cells that function as filters that trap pathogens to help fight the infection and swell near the infection site. An abscess will also cause a feeling of heat or warmth as there is increased blood flow to the area, causing inflammation that helps to clear necrotic cells and initiate healing and repair of the infected area. A tooth abscess can also result in a pulsating headache, due to its close proximity to the trigeminal nerves, which are nerves connected to the brain and conduct sensations to areas of the face. This can also trigger migraine headaches in some people, as well as nausea, vomiting, and a sensitivity to light.