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Subarachnoid Hemorrhage

What is a subarachnoid hemorrhage?

A subarachnoid hemorrhage is a life-threatening type of stroke caused by bleeding in the space around the brain. The medical emergency occurs when an artery bursts and the blood mixes with cerebrospinal fluid, increasing pressure around the brain. That increased pressure can interfere with brain function. With rapid response and the proper medical care, patients can recover.

Causes of subarachnoid hemorrhage

The most common cause of subarachnoid hemorrhage is an aneurysm, which accounts for about 85 percent of cases. An arteriovenous malformation or traumatic brain injury could also trigger a subarachnoid hemorrhage. These most frequently happen after the age of 40. Risk factors include smoking, drug use, and high blood pressure.

Signs of a subarachnoid hemorrhage

An intense, sudden headache in the back of the head is the most common symptom of subarachnoid hemorrhage. Other symptoms include nausea, vomiting, dizziness, seizures, sensitivity to light, and a loss of consciousness. Drooping eyelids and speech problems can also be symptoms.


A doctor will discuss your symptoms and medical history. They will conduct a physical and neurological exam, and order imaging tests to map the brain and blood flow. A CT scan or an MRI can detect bleeding in the brain. More than 20 percent of initial imaging misses a subarachnoid hemorrhage. If initial tests do not reveal bleeding, your doctor may recommend repeating the test or performing a lumbar puncture, or spinal tap, to test for blood in the fluid around the spinal cord and brain.


Surgery is most commonly used to stabilize a subarachnoid hemorrhage. A metal clip is placed to stop the bleeding. It is also possible for a surgeon to perform an endovascular embolization, where platinum coils are placed through a catheter to fill the aneurysm and help the blood clot. In some cases, a stent or balloon angioplasty can be performed to divert the blood flow.

What You Can Expect at UTHealth Neurosciences

At UTHealth Neurosciences, our dedicated team of neurosurgeons and other specialists use the latest technology to accurately diagnose and treat patients. We work in multidisciplinary teams to share insights, leading to better treatment decisions and outcomes. Throughout the treatment process, we will work closely with the doctor who referred you to ensure a smooth transition back to your regular care. While you are with us, you will receive expert care, excellent communication, and genuine compassion.

Cerebrovascular and Stroke Care

Contact Us

At UTHealth Neurosciences, we offer patients access to specialized neurological care at clinics across the greater Houston area. To ask us a question, schedule an appointment, or learn more about us, please call (713) 486-8000, or click below to send us a message. In the event of an emergency, call 911 or go to the nearest Emergency Room.