A hemorrhagic stroke happens when a blood vessel in or around the brain ruptures, allowing blood to spill into surrounding tissue. Unlike the more common ischemic stroke, which is caused by a clot blocking blood flow, a hemorrhagic stroke involves active bleeding. It accounts for 10% to 15% of all strokes globally but is far more deadly, with 30-day mortality rates around 30% to 40%.
Two Types of Hemorrhagic Stroke
Hemorrhagic strokes are classified by where the bleeding occurs. In an intracerebral hemorrhage, a blood vessel bursts inside the brain tissue itself. This is the more common type, and it typically results from years of high blood pressure weakening small arteries deep in the brain. Those weakened vessels eventually give way, and blood pools directly in the brain, destroying cells and creating dangerous pressure.
A subarachnoid hemorrhage is bleeding into the fluid-filled space surrounding the brain rather than inside it. The most common non-traumatic cause is a ruptured cerebral aneurysm, a balloon-like weak spot in an artery wall that bursts and releases blood around the brain’s surface. Subarachnoid hemorrhages can also result from head injuries, which damage the smaller vessels along the brain’s outer layer.
What Causes Blood Vessels to Rupture
Chronic high blood pressure is the leading cause. Over years, elevated pressure damages the walls of the small arteries that feed deep brain tissue, a process called lipohyalinosis. The vessel walls become stiff, fragile, and prone to breaking. This is why blood pressure management is the single most important factor in preventing hemorrhagic stroke. The American Heart Association recommends that most people who need medication for high blood pressure take two or more drugs, since a single medication only gets blood pressure to goal in about 30% of patients.
Other causes include ruptured aneurysms, abnormal tangles of blood vessels (arteriovenous malformations), brain tumors, infections, and blood-thinning medications. Smoking substantially increases risk. A large meta-analysis found that smokers face nearly double the risk of intracerebral hemorrhage and more than triple the risk of subarachnoid hemorrhage compared to nonsmokers.
Pregnancy and the first six weeks after delivery also carry heightened risk. Blood pressure that reaches 160/110 or higher during this period is treated as a neurological emergency because of the danger of fatal brain bleeding.
Symptoms and Warning Signs
Hemorrhagic stroke shares the classic stroke symptoms: sudden weakness or numbness on one side of the body, difficulty speaking or understanding speech, and trouble with balance or coordination. But it often has features that distinguish it from a clot-based stroke.
The hallmark of a subarachnoid hemorrhage is a thunderclap headache, an explosive headache that reaches peak intensity in under a minute. It is frequently described as the worst headache of a person’s life. This headache may come with neck stiffness, vomiting, sensitivity to light, confusion, or loss of consciousness. Some people experience a less severe “sentinel” headache days or weeks before the major rupture, essentially a small warning leak from the aneurysm.
Intracerebral hemorrhage can also cause a severe headache, but it more often presents with rapidly worsening neurological problems: progressive weakness, vision loss on one side, difficulty with language, or a declining level of consciousness. The symptoms tend to worsen over minutes to hours as bleeding continues and pressure builds inside the skull.
How Severity Is Assessed
When someone arrives at a hospital with a brain bleed, doctors use imaging (typically a CT scan) and clinical findings to gauge severity. For intracerebral hemorrhage, key factors include the person’s age, the volume of blood in the brain, whether blood has spread into the brain’s fluid-filled chambers (the ventricles), and the person’s level of consciousness at admission.
Each of these factors independently predicts survival. A bleed volume of 30 milliliters or more nearly quadruples the odds of dying within 30 days. Being over 80 more than doubles mortality risk. When blood extends into the ventricles, the odds of death roughly triple. In the most severe cases, where multiple risk factors overlap, mortality approaches 100%. In milder presentations, survival rates are much more favorable.
How It’s Treated
Treatment depends on the type, location, and cause of the bleeding. The immediate priorities are stabilizing blood pressure, stopping active bleeding if possible, and preventing the brain from swelling further.
For people taking blood thinners when a bleed occurs, reversing the medication’s effect is urgent. Each class of blood thinner has a specific antidote. The reversal agents work within minutes and are given intravenously to restore the blood’s ability to clot and stop the hemorrhage from expanding.
Subarachnoid hemorrhages caused by a ruptured aneurysm require a procedure to seal off the aneurysm and prevent re-bleeding. There are two main approaches. Surgical clipping involves opening the skull and placing a tiny metal clip at the base of the aneurysm to shut it off from blood flow. Endovascular coiling is less invasive: a catheter is threaded through an artery to the aneurysm, where tiny coils are packed inside it to promote clotting and seal the bulge. The choice depends on the patient’s age, the aneurysm’s size and location, and the hospital’s resources. Younger patients with small aneurysms near the front of the brain tend to do well with clipping, while aneurysms in the back of the brain are harder to reach surgically and are more often treated with coiling.
For intracerebral hemorrhage, surgery to remove the pooled blood is sometimes performed, particularly when the bleed is large, accessible, and causing dangerous pressure. In many cases, though, management is medical rather than surgical, focused on controlling blood pressure, reducing brain swelling, and supporting the patient through the acute phase.
Recovery and Long-Term Outcomes
Hemorrhagic stroke survival rates vary widely by region. In high-income countries, 25% to 30% of patients die within the first month. In lower-income countries, that figure rises to 30% to 48%, largely due to differences in access to emergency care and neurosurgery.
For survivors, the early weeks can be misleading. Neurological function is often at its worst in the days immediately following the bleed, partly because of swelling and other acute complications rather than permanent damage. As swelling resolves and the brain begins to heal, many people improve significantly. More than 40% of stroke survivors recover to good functional outcomes within one year.
Recovery timelines vary enormously depending on the bleed’s size and location, the person’s age, and the intensity of rehabilitation. The fastest gains typically happen in the first three months, but meaningful improvement can continue well beyond that window. Rehabilitation usually involves physical therapy, occupational therapy, and speech therapy tailored to the specific deficits the person experiences. Some survivors regain near-complete independence, while others live with lasting disabilities in movement, speech, or cognition.
Reducing Your Risk
Because high blood pressure drives the majority of hemorrhagic strokes, keeping it under control is the most effective prevention strategy. This means regular monitoring, consistent use of prescribed medications, and lifestyle factors like reducing sodium intake, staying physically active, and maintaining a healthy weight.
Quitting smoking is the second most impactful change. The elevated stroke risk from smoking applies regardless of age, sex, or how much a person smokes. Combining a quit-smoking medication with behavioral counseling works better than counseling alone.
Limiting heavy alcohol use, managing conditions like diabetes that damage blood vessels, and working with your doctor to carefully weigh the risks and benefits of blood-thinning medications all further reduce the chance of a hemorrhagic stroke.