Subarachnoid hemorrhage is a serious condition caused by bleeding in the space between the brain and the surrounding membrane (subarachnoid space). When a hemorrhage occurs in the subarachnoid space, an individual may experience coma, paralysis and even death.

Bleeding in the brain usually results from the rupture of an abnormal bulge in a blood vessel. If left untreated, a subarachnoid hemorrhage can lead to permanent brain damage or death.



The main symptom of subarachnoid hemorrhage is a severe, throbbing headache. It may start after a popping or snapping feeling in the head. Other common signs and symptoms may include:

  • Neck pain
  • Shoulder pain
  • Numbness
  • Nausea and vomiting
  • Confusion
  • Sensitivity to light
  • Seizures
  • Irritability
  • Blurred or double vision
  • Decreased alertness


The main cause related to subarachnoid hemorrhage is a brain aneurysm rupturing. A brain aneurysm is swelling in a blood vessel, caused by weakness in the blood vessel wall. Other causes of subarachnoid hemorrhage include:

  • Bleeding from an arteriovenous malformation
  • Bleeding disorder
  • Bleeding from a cerebral aneurysm
  • Head injury
  • Use of blood thinners

Risk factors

Factors that can increase the risk of developing a subarachnoid hemorrhage include the following:

  • Being a smoker
  • Having high blood pressure
  • Having a personal history of polycystic kidney disease
  • Having a family history of aneurysms
  • Having an aneurysm in other blood vessels
  • Having Fibromuscular dysplasia (FMD) or other connective tissue disorders



The most severe complication that arises from a subarachnoid hemorrhage is repeated bleeding. Other possible complications that can arise from a subarachnoid hemorrhage include:

  • Complications for surgical procedures
  • Side effects from certain medications
  • Epilepsy
  • Stroke
  • Coma
  • Death



Treatment options for subarachnoid hemorrhage focus on reducing the likelihood of brain damage, by repairing the cause of bleeding and relieving symptoms to prevent further complications.

A doctor may recommend the following:

  • Medicines given through an IV to regulate blood pressure levels
  • Medications used to relieve headache and alleviate pressure in the skull
  • Medications used to prevent or treat seizures
  • Stool softeners or laxatives used to regulate bowel movements


Treatment methods for individuals in a coma or with decreased alertness include:

  • Life support with synthetic ventilation
  • Protection of the airways
  • Insertion of a tube in the brain to drain excess fluid and alleviate pressure in the skull

Surgical treatment methods are performed in order to help close the aneurysm, stop future bleeding by removing large collections of blood and alleviate pressure on the brain if the hemorrhage is due to an injury. These methods may include:

  • Craniotomy: A surgical procedure that involves cutting a hole into the skull to close to aneurysm.
  • Endovascular coiling: A surgical procedure that involves placing coils in the aneurysm and stents in the blood vessel to cage the coils and reduce the risk of further bleeding.



The only way to prevent a subarachnoid hemorrhage is to recognize the potential problems within the brain. Early detection and proper diagnosis of a brain aneurysm can prevent a hemorrhage in the subarachnoid space.