Mayo Clinic doctors trained in brain and nervous system surgery (neurosurgery), brain and nervous system conditions (neurology), brain imaging (neuroradiology), and other areas work as a team to diagnose subarachnoid hemorrhage, determine the cause of your condition and quickly develop the most appropriate treatment plan for you.
To diagnose your condition, your doctor may evaluate your symptoms, including any unexpected, severe headaches. Your doctor may order tests to diagnose and determine the cause of your condition.
- Computerized tomography (CT) scan. A CT scan uses a series of X-rays to create detailed cross-sectional images of your brain and blood vessels. CT scans can help detect bleeding in your brain. Your doctor may inject a contrast dye to view your blood vessels in greater detail (CT angiogram).
- Magnetic resonance imaging (MRI). An MRI uses powerful magnetic field and radio waves to create detailed images of your brain and blood vessels. An MRI can help detect bleeding in your brain, and may help determine the underlying cause for the bleeding. Your doctor may inject a dye into a blood vessel to view your blood vessels and show the blood circulation in your brain (magnetic resonance angiogram).
- Lumbar puncture. If your doctor suspects a subarachnoid hemorrhage, but the hemorrhage doesn't appear on a CT scan, your doctor may order a lumbar puncture. In this test, a doctor will insert a needle into your lower back to withdraw a small amount of fluid that surrounds your brain and spinal cord (cerebrospinal fluid). Your doctor will examine the cerebrospinal fluid for the presence of blood.
- Cerebral angiography. In this test, a doctor inserts a long, thin tube (catheter) into an artery in your leg and threads it to your brain. A doctor injects dye into the blood vessels of your brain to make them visible under X-ray imaging.
Read more about CT scan, MRI and lumbar puncture.