Neurosurgeon Explains What Happens When the Brain Bleeds

Few neurological conditions are as time-sensitive or as potentially devastating as a brain bleed. As part of ongoing efforts to increase brain injury awareness, medical experts highlight the critical differences between various types of intracranial hemorrhages and the warning signs that necessitate immediate medical intervention.

In a recent Baptist Health Instagram reel, Robert Wicks, M.D., co-director of cerebrovascular surgery and director of the Neurosurgical Anatomy Laboratory at Baptist Health Miami Neuroscience Institute, provided a detailed overview of what occurs when the brain bleeds and how patients can recognize the symptoms before they become life-threatening.

The Mechanics of a Brain Bleed

When a hemorrhage occurs within the skull, the internal environment of the brain changes rapidly. Dr. Wicks explains that the impact on the patient depends largely on the location and the cause of the bleeding.

“What actually happens inside the brain when it bleeds is that you can have two different types of bleeding within the brain,” Dr. Wicks stated.

According to Dr. Wicks, these two primary categories often present with vastly different clinical pictures, ranging from an explosive "thunderclap" headache to a slow, subtle decline in cognitive and physical function.

Arterial Ruptures: The Sudden Threat

The first type of bleeding involves the high-pressure arterial system. One of the most common causes of this type of acute hemorrhage is an aneurysm.

“The first type is that you have a weakness or an out-pouching in an artery and that's called an aneurysm,” Dr. Wicks explained.

When an aneurysm ruptures, it releases blood directly into the space surrounding the brain at high pressure. This leads to a distinct and terrifying symptom that patients often describe as the most painful experience of their lives.

“You experience a sudden-onset severe headache — unlike anything else you've had before,” said Dr. Wicks. This sudden, severe headache is a hallmark of a subarachnoid hemorrhage and requires emergency medical evaluation.

Chronic Subdural Hematomas: The Slow Onset

Not all brain bleeds are characterized by a sudden explosion of pain. Some develop over days or even weeks, often following an event that the patient might have initially dismissed.

“Another type of headache that is concerning [follows] a fall or a very minor trauma and we frequently see this in people as they get a little bit older,” Dr. Wicks noted.

In these cases, the bleeding is often venous rather than arterial, occurring in the space between the brain's surface and its outermost covering. This is known as a chronic subdural hematoma. Because the pressure builds more slowly, the symptoms may be mistaken for general aging or other less serious conditions.

Visualizing this condition through imaging, Dr. Wicks pointed out the physical displacement that occurs: “Normally, you would see the brain right under the bone of the skull.” But with a brain bleed, “what you can see is that you have this large area of dark fluid. This is what we call a chronic subdural hematoma.”

Recognizing the Warning Signs

While a sudden, severe headache is the primary red flag for an acute bleed, the symptoms of a slow-developing bleed are more diverse. Dr. Wicks urges patients to pay close attention to persistent changes in their baseline health.

The warning signs of a chronic subdural hematoma include:

• Daily, persistent headaches that do not resolve.
• New difficulties with balance or walking.
• Noticeable changes in speech or word-finding.

“And so if you're experiencing daily headaches and any other symptoms such as difficulty with walking or speech problems — then it's important to seek care as soon as possible,” Dr. Wicks advised.

The Importance of Early Evaluation

The common thread in all types of brain bleeding is that early detection significantly improves outcomes. Whether the cause is a structural weakness like an aneurysm or a trauma-induced hematoma, medical intervention can stop the bleeding, manage intracranial pressure, and prevent further damage to brain tissue.

In addition to neurological health, experts remind the public that listening to your body is a universal rule for wellness. Stopping activities when something feels wrong and seeking a professional evaluation can protect the heart and the brain alike.

For those experiencing any of the symptoms described by Dr. Wicks—especially a "first and worst" headache or a combination of daily headaches with motor or speech issues—the message is clear: do not wait. Early evaluation is the most effective tool in the fight against the permanent effects of a brain injury.