Who Should Undergo Diagnostics and When to Seek Them

If you suddenly experience a severe headache that feels like being hit on the head, numbness on one side of your body, confusion, or difficulty speaking, you need to call emergency services immediately. These symptoms can signal a brain bleed, and waiting even a few minutes can make the difference between recovery and permanent damage. Brain cells begin to die within three to four minutes when they don’t receive oxygen, so recognizing the warning signs early is essential.^[1]

Anyone who has suffered a head injury—whether from a fall, car accident, sports collision, or bicycle crash—should seek medical attention right away, even if they feel fine at first. Symptoms of intracranial hemorrhage can develop immediately or over several hours, days, or even weeks after the injury. This slow progression means that pressure inside your skull is gradually building, and the damage becomes more severe over time.^[1][15]

People with certain health conditions are at higher risk and should be especially alert. If you have unmanaged high blood pressure, take blood-thinning medications like warfarin or aspirin, or are over 65 years old, even a minor bump on the head can cause bleeding inside your skull. Individuals who have had a previous stroke, use recreational drugs like cocaine or amphetamines, or have a history of liver disease or bleeding disorders should also be vigilant.^[4][15]

Pregnant women who experience sudden severe headache, vision changes, or neurological symptoms should also seek immediate evaluation, as brain bleeds can occur during pregnancy and require specialized care. The same applies to children—infants born prematurely are at risk for a type of brain bleed called subependymal or germinal matrix hemorrhage, and any child with unexplained neurological symptoms after a head injury needs urgent assessment.^[4]

Classic Diagnostic Methods Used to Identify the Disease

When you arrive at the emergency department with symptoms suggesting a brain bleed, doctors will act quickly to confirm the diagnosis and pinpoint the exact location of the bleeding. The first and most important diagnostic tool is a computed tomography (CT) scan, which is a special type of X-ray that creates detailed cross-sectional images of your brain. A CT scan is the preferred test for diagnosing intracranial hemorrhage because it is fast, widely available, and extremely effective at showing fresh blood inside the skull or brain tissue.^[1][3]

During a CT scan, you lie still on a movable table that slides into a large, doughnut-shaped machine. The machine rotates around your head, taking multiple images from different angles. These images are then combined by a computer to create a three-dimensional picture of your brain. The entire process usually takes only a few minutes, which is why it’s the go-to test when time is critical. Blood appears bright white on a CT scan, making it easy for doctors to see where the bleeding is happening and how much blood has accumulated.^[1][11]

If the CT scan confirms a brain bleed, your doctor may order additional imaging tests to understand the cause of the bleeding. A CT angiography (CTA) involves injecting a special dye directly into your bloodstream through an intravenous line. This dye makes your blood vessels show up clearly on the CT images, allowing doctors to see if there is an aneurysm (a bulge in a blood vessel), an arteriovenous malformation (an abnormal tangle of blood vessels), or another vascular problem that caused the bleed.^[3][5]

Another advanced imaging method is a cerebral angiogram, which provides even more detailed pictures of the blood vessels in your brain. During this procedure, a thin, flexible tube called a catheter is inserted into an artery in your groin or arm and carefully threaded through your circulatory system all the way up to your brain. Once the catheter is in place, dye is injected through it, and X-ray images are taken. This test can show very small aneurysms or vascular abnormalities that might not be visible on a CT scan.^[3][5]

In some cases, doctors may use a magnetic resonance imaging (MRI) scan instead of or in addition to a CT scan. An MRI uses powerful magnets and radio waves to create detailed images of your brain’s soft tissues. While MRI scans take longer than CT scans and are not usually the first choice in an emergency, they can be very helpful in detecting smaller bleeds, older bleeds, or bleeding in certain parts of the brain that are harder to see on CT. MRI is particularly useful when doctors need to understand the extent of brain tissue damage or identify underlying conditions like vascular malformations.^[3][11]

If there is suspicion of bleeding in the space surrounding the brain—a type called subarachnoid hemorrhage—and imaging tests are not conclusive, doctors may perform a lumbar puncture, also known as a spinal tap. During this procedure, a thin needle is inserted into the lower part of your spine to collect a small sample of cerebrospinal fluid, the clear liquid that surrounds and cushions your brain and spinal cord. If blood is present in this fluid, it confirms that bleeding has occurred in or around the brain.^[3][5]

Beyond imaging, doctors will perform a thorough physical examination and ask detailed questions about your symptoms, medical history, and any recent injuries. They will check your blood pressure, heart rate, breathing rate, and temperature—these are called vital signs—and assess your level of consciousness using a scale that measures your ability to open your eyes, speak, and move. This neurological examination helps doctors understand how much the brain has been affected and whether the pressure inside your skull is rising.^[2][13]

Laboratory blood tests are also part of the diagnostic process. Doctors will check your blood count, kidney function, liver function, and how well your blood clots. If you are taking blood-thinning medications, these tests are especially important because they help guide treatment decisions. For example, if your blood is not clotting properly, doctors may need to give you medications or other treatments to reverse the effects of blood thinners and stop the bleeding.^[2][11]

In some situations, doctors may order repeat CT scans hours or days after the first one. This is because brain bleeds can expand over time—studies show that up to 38% of hemorrhages grow within the first three hours after they start. Monitoring the size of the bleed helps doctors decide whether surgery is needed or whether medical treatment alone will be enough.^[9][12]

Diagnostics for Clinical Trial Qualification

When patients with intracranial hemorrhage are considered for enrollment in clinical trials, a specific set of diagnostic tests and criteria must be met to ensure they are suitable candidates. Clinical trials test new treatments or approaches to care, and they require precise documentation of the patient’s condition at the time of enrollment. These tests help researchers understand exactly what type of brain bleed occurred, how severe it is, and whether the patient meets the study’s inclusion or exclusion criteria.^[9][12]

The first requirement is usually a confirmed diagnosis of intracranial hemorrhage using a non-contrast CT scan of the brain. This scan must clearly show the presence of bleeding and allow researchers to measure the volume of the hemorrhage. The size of the bleed is often calculated using specific formulas based on the CT images, and this measurement is one of the key factors that determine whether a patient can join the trial. For example, some studies only include patients with hemorrhages of a certain size—either larger or smaller than a specific threshold.^[9][12]

Timing is also critical for clinical trial enrollment. Many trials require that patients be enrolled within a very short window after the onset of symptoms—sometimes as little as three to four hours. This is because the first few hours after a brain bleed begins are considered the “golden window” when treatments may be most effective. To confirm the timing, doctors rely on the patient’s or family’s account of when symptoms started, combined with the findings on the initial CT scan.^[9]

Blood pressure measurements are another standard criterion. Because high blood pressure is a major cause of brain bleeds and can also worsen the hemorrhage, clinical trials often have strict blood pressure requirements. Some studies focus on patients with very high blood pressure at the time of presentation, while others may exclude patients whose blood pressure is too high or too difficult to control.^[12][14]

Laboratory tests play a key role in determining trial eligibility as well. Researchers need to know the patient’s baseline blood counts, kidney function, liver function, and clotting ability. If a patient is taking anticoagulant medications (blood thinners) or has a bleeding disorder, this information is essential because it affects both the cause of the hemorrhage and the safety of any experimental treatment. Trials focused on reversing the effects of blood thinners, for example, specifically seek out patients who were on these medications when the bleed occurred.^[11][12]

Additional imaging studies, such as CT angiography or MRI, may be required to rule out certain causes of bleeding. For instance, if a trial is testing a treatment for spontaneous hemorrhage caused by high blood pressure, patients with bleeding due to aneurysms, arteriovenous malformations, tumors, or trauma would typically be excluded. These imaging tests help researchers ensure that the group of patients in the study is as similar as possible, which makes the results more reliable.^[4][9]

Neurological assessment is another key component. Researchers use standardized scales to measure the patient’s level of consciousness, ability to move, speak, and respond to commands. One commonly used scale is the Glasgow Coma Scale, which assigns a score based on eye opening, verbal response, and motor response. These scores help researchers classify the severity of the brain injury and monitor changes over time. Clinical trials often have specific score ranges for inclusion—for example, they may only enroll patients who are conscious and able to follow commands, or they may focus on patients with more severe impairment.^[2][13]

Some trials also require tests to assess the patient’s overall health and ability to tolerate the experimental treatment. This might include an electrocardiogram (ECG) to check heart function, chest X-rays, or additional blood tests. If the trial involves surgery or a procedure, patients may need to undergo tests to ensure they are stable enough for the intervention.^[10]

Documentation of informed consent is also part of the diagnostic and enrollment process. Because many patients with brain bleeds have altered consciousness or confusion, obtaining consent can be complex. In some cases, family members or legally authorized representatives provide consent on behalf of the patient. Researchers must carefully document the patient’s mental status and capacity to understand the trial before proceeding.^[9]

Serial imaging—meaning repeated CT scans at specific intervals—is often required during clinical trials to monitor whether the hemorrhage is expanding or stabilizing. This helps researchers understand whether the experimental treatment is working and whether it is safe. The timing and frequency of these scans are carefully planned as part of the trial protocol.^[9][12]

Finally, clinical trials may require additional specialized tests depending on the treatment being studied. For example, if a trial is testing a new drug to reduce brain swelling, researchers might use advanced imaging techniques to measure the amount of swelling before and after treatment. If the trial involves a surgical procedure, detailed brain imaging and measurements of intracranial pressure may be needed to guide the intervention and assess its success.^[10]