Subarachnoid hemorrhage (SAH) is a type of bleeding that occurs in the space between the brain and the thin tissues that cover it. Here are the answers to your questions:

Cause of subarachnoid hemorrhage: The main cause of subarachnoid hemorrhage is the rupture of a weakened blood vessel in the subarachnoid space. The most common cause of this rupture is the presence of a cerebral aneurysm—a weak or bulging area in a blood vessel wall. Other potential causes include head trauma, arteriovenous malformations (AVMs), blood clotting disorders, and certain medications.

Complications of subarachnoid hemorrhage: Two common complications associated with subarachnoid hemorrhage are:

Vasospasm: After the initial bleeding, the blood vessels in the brain may undergo spasm or narrowing, leading to reduced blood flow. This can potentially cause additional brain damage and neurological deficits.

Hydrocephalus: Subarachnoid hemorrhage can disrupt the normal flow and absorption of cerebrospinal fluid (CSF), leading to an accumulation of fluid in the brain, a condition known as hydrocephalus. This can cause increased pressure within the skull and may require treatment such as drainage through a shunt.

Treatability of subarachnoid hemorrhage: Subarachnoid hemorrhage is a medical emergency and requires immediate medical attention. Treatment depends on the underlying cause, severity, and complications. It may involve measures such as stabilization of vital signs, supportive care, medications to prevent vasospasm and control symptoms, and surgical interventions to repair the source of bleeding (e.g., aneurysm clipping or endovascular coiling).

Types of subarachnoid hemorrhage: There are two main types of subarachnoid hemorrhage based on the origin of bleeding:

Aneurysmal subarachnoid hemorrhage: This type occurs due to the rupture of a cerebral aneurysm.

Non-aneurysmal subarachnoid hemorrhage: In some cases, bleeding in the subarachnoid space may occur without the presence of an aneurysm. The exact cause of non-aneurysmal subarachnoid hemorrhage is often unclear and may be related to factors such as small blood vessel abnormalities, bleeding disorders, or trauma.

Prompt medical intervention is essential in subarachnoid hemorrhage to minimize the risk of complications, improve outcomes, and provide appropriate treatment based on the individual's condition and underlying cause.