A brain abscess is a pocket of infection that forms in the brain. Depending on its size and location, a brain abscess may cause headaches, personality changes, one-sided weakness, fever and chills, nausea and vomiting, and seizures.

Brain abscesses are uncommon. They may be caused by:

• The spread of infection from somewhere else in the head, such as the gums (gingivitis), mouth, nose, ear, or sinus.
• A deep head wound that penetrates the brain.
• Infection that has traveled through the bloodstream from somewhere else in the body.

Treatment includes medicine to fight the infection and decrease swelling in the brain. In some cases a brain abscess requires surgical drainage.