What is the primary cause of brain swelling?

• A. Strokes
• B. Direct trauma or injury to the brain
• C. Edema
• D. Brain tumor

Answer: (B)

Cerebral edema is swelling of brain tissue caused by excess fluid accumulation due to disruption of cellular homeostasis and the blood-brain barrier. Direct trauma to the brain is the most immediate trigger for this swelling because injury damages brain cells and blood vessels, triggering inflammatory responses and increased vascular permeability that drive fluid into the brain tissue. While strokes and brain tumors can cause edema as well, they are not the initial trigger in the common acute swelling scenario—the injury itself starts the cascade. Remember, edema describes the fluid buildup; the injury is the event that initiates that process.