Final answer:
Carotid artery dissection is a condition where the layers of the carotid artery tear and separate, leading to reduced blood flow to the brain. Common symptoms include severe headache, neck pain, dizziness, vision changes, and difficulty speaking.
Step-by-step explanation:
Carotid artery dissection occurs when the layers of the carotid artery wall tear and separate from each other. This can lead to the narrowing or complete blockage of the artery, reducing blood flow to the brain. The symptoms of carotid artery dissection can vary depending on the location and extent of the tear, but common symptoms include sudden severe headache, neck pain, dizziness, vision changes, and difficulty speaking or understanding speech.