The main symptom of a subarachnoid hemorrhage is a thunderclap headache, which is a very intense and painful headache that comes on suddenly. Other symptoms of subarachnoid hemorrhage can include: Decreased consciousness and alertness. Nausea and vomiting. Stiff neck. Sudden weakness. Mood and personality changes, including confusion and irritability. Dizziness. Eye sensitivity in bright light (photophobia). Muscle aches, especially in your neck and shoulders. Numbness in part of your body. Seizures. Vision changes, including double vision, blind spots or temporary vision loss in one eye.