• Headache
  • Sudden onset
  • Described as the "worst ever experience"
  • Can be preceded by a popping or snapping sensation in the head
  • Pain described as a new type
  • Generalized pain, often worse near the back of the head
• Nausea and vomiting may accompany the headache
• Decreased consciousness and alertness
  • Temporary or progressively worsens to coma and death
• Difficulty seeing or changes in vision
  • Double vision
  • Blind spots
  • Temporary loss of vision in one eye
• Stiff neck
• Photophobia (light bothering or hurting the eyes)
• Muscle aches (especially neck pain and shoulder pain)
• Seizure or spell
• Difficulty or loss of movement or sensation of a part of the body
• Changes in mood and personality
  • Confusion
  • Irritability

Additional symptoms that may be associated with this disease:

• Eyes, pupils different size
• Eyelid drooping
• Opisthotonos (not very common)

A neuromuscular examination usually indicates meningeal irritation. The neck may be stiff and movement of the neck may be resisted in all but deeply comatose people. There may be indications of focal neurologic deficit (localized decreases in nerve/brain function). An examination of the eyes may indicate bleeding in the brain. It may also show decreased eye movements and changes that indicate damage to the 3rd or 6th cranial nerves.

• Head CT scan (preferred) or an MRI that shows blood in the subarachnoid area. This should be performed before lumbar puncture (spinal tap). If the CT demonstrates blood in the subarachnoid space, a lumbar puncture is no longer necessary.
• A cerebrospinal fluid examination (spinal tap) that shows blood.
• Angiography of blood vessels of the brain (cerebral angiography) that shows small aneurysms or other vascular anomaly and the exact location of the bleed.

This disease may also alter the results of CPK isoenzymes.