Subarachnoid Hemorrhage: Causes, Signs, and What You Need to Know

When blood leaks into the space around the brain—called the subarachnoid hemorrhage, a type of bleeding that occurs between the brain and the thin tissues covering it. Also known as SAH, it’s not a stroke in the traditional sense, but it acts like one: sudden, severe, and often deadly if not treated fast. This isn’t a slow-developing condition. People usually describe it as the worst headache of their life, hitting like a lightning strike. It’s often caused by a ruptured aneurysm, a weak, balloon-like bulge in a brain artery that bursts under pressure. About 85% of cases come from this source. The rest? Trauma, blood disorders, or rare vascular malformations.

What makes subarachnoid hemorrhage so dangerous isn’t just the bleeding—it’s what happens after. Blood in the subarachnoid space can trigger spasms in nearby arteries, cutting off oxygen to parts of the brain. This is called vasospasm, and it’s a leading cause of death or disability even after the initial bleed is stopped. That’s why hospitals rush to scan the brain with CT, then do an angiogram to find the source. If an aneurysm, a weak, balloon-like bulge in a brain artery that bursts under pressure. is found, surgeons may clip it or use coils to seal it off. Time matters—every minute counts.

Not everyone survives. About 40% of people die within the first 24 hours. Of those who make it to the hospital, many face long-term problems: memory loss, trouble concentrating, depression, or even paralysis. Recovery isn’t just about surviving the bleed—it’s about managing the ripple effects. That’s why rehab, monitoring for vasospasm, and controlling blood pressure are just as critical as the initial surgery.

You won’t always see warning signs before a rupture. Some people have small "sentinel" headaches days before, but most don’t. That’s why knowing the red flags is your best defense. Sudden, explosive headache. Neck stiffness. Nausea, vomiting, confusion, or loss of consciousness. If someone has these—call 911. No waiting. No driving yourself. This isn’t a migraine. It’s a brain bleed, a medical emergency where blood escapes into spaces around the brain. and it demands immediate action.

The posts below cover what you need to know beyond the basics: how medications like warfarin raise bleeding risk, how to spot dangerous drug interactions that could worsen outcomes, and what steps patients and families can take after a diagnosis. You’ll find real advice on monitoring, recovery, and avoiding complications—not just theory. This isn’t about guessing. It’s about knowing what to do when every second counts.