What is the most common symptom associated with a ruptured intracranial aneurysm?

A ruptured intracranial aneurysm commonly presents with a severe headache, often described as a "thunderclap headache" or the "worst headache of my life." This intense pain is due to the sudden release of blood into the subarachnoid space, leading to increased intracranial pressure and irritation of the meninges. The acute onset and severe nature of the headache make it a hallmark symptom of this condition, and it typically prompts individuals to seek immediate medical attention.

While changes in consciousness, nausea, and vomiting, as well as visual changes, can occur following a ruptured aneurysm, they are less specific and may result from complications associated with the bleeding, such as increasing intracranial pressure, vasospasm, or irritation of nearby structures. The severe headache remains the most immediate and distinctive symptom that characterizes the acute phase of a separated intracranial aneurysm.