Signs and Symptoms of Subarachnoid Hemorrhage: What You Need to Know

Subarachnoid hemorrhage (SAH) is a life-threatening type of stroke caused by bleeding into the space surrounding the brain. Recognizing its hallmark signs early can significantly improve outcomes and reduce complications. This condition often develops suddenly and requires immediate medical attention. Below, we explore the key clinical features associated with SAH, helping patients and caregivers identify warning signals before irreversible damage occurs.

Sudden and Severe Headache: The Hallmark Symptom

One of the most defining characteristics of subarachnoid hemorrhage is the abrupt onset of an excruciating headache. Often described as "the worst headache of my life," this pain typically peaks within seconds to minutes after onset. Patients frequently recall the exact moment it began—whether they were exercising, straining during bowel movements, coughing, drinking alcohol, or experiencing intense emotional stress. While physical triggers are common, some cases occur even at rest.

In approximately one-third of cases, individuals may experience warning symptoms days before the actual rupture—such as mild headaches, nausea, or vomiting—often overlooked as minor health issues. When the bleed occurs, the headache becomes explosive and throbbing, affecting the entire head (holocranial). The pain is usually persistent and progressively worsens over time. Some patients also report pain radiating to the upper neck, especially if the aneurysm is located near critical brainstem areas.

This sudden neurological event may be accompanied by additional signs such as nausea, vomiting, and photophobia. In certain instances, focal neurological deficits—including weakness on one side of the body, speech difficulties, or sensory disturbances—may also appear depending on the location and severity of the bleed.

Neck Stiffness and Meningeal Irritation Signs

Neck stiffness, or nuchal rigidity, is another classic indicator of SAH. It typically develops several hours after the initial bleed due to blood irritating the meninges—the protective layers covering the brain and spinal cord. This symptom often coexists with other signs of meningeal irritation, including sensitivity to light (photophobia), repeated vomiting, and discomfort when bending the neck forward.

Patients might also complain of back pain, particularly in the upper spine, which results from the spread of blood into the subarachnoid space along the spinal canal. Eye examination can reveal crucial clues: retinal hemorrhages and papilledema (swelling of the optic disc) are occasionally observed during fundoscopic evaluation, further supporting the diagnosis.

Altered Mental Status and Neurological Complications

A significant proportion of patients—around 25%—experience changes in mental status following a subarachnoid hemorrhage. These can range from confusion and agitation to hallucinations and delirium. In more severe cases, seizures may occur due to cortical irritation from blood products in the subarachnoid space.

Additionally, cranial nerve involvement is not uncommon. For example, oculomotor nerve palsy (cranial nerve III) may manifest as drooping eyelids, double vision, or a dilated pupil—especially when the posterior communicating artery aneurysm compresses the nerve. Other possible deficits include aphasia (difficulty speaking), hemiparesis (partial paralysis on one side), and sensory loss.

Atypical Presentations in Older Adults

It's important to note that elderly patients may not always present with the classic triad of thunderclap headache, vomiting, and neck stiffness. Instead, their symptoms can be subtle or misleading. Cognitive changes, lethargy, or generalized weakness may dominate the clinical picture, making early diagnosis more challenging.

In these cases, clinicians must maintain a high index of suspicion, especially when dealing with older individuals who suddenly develop unexplained confusion or altered consciousness. Delayed recognition increases the risk of rebleeding, vasospasm, hydrocephalus, and long-term disability.

Early detection and rapid intervention remain the cornerstone of managing subarachnoid hemorrhage. If you or someone around you experiences a sudden, severe headache—especially with neurological symptoms—seek emergency medical care immediately. Timely imaging, such as non-contrast CT scans or lumbar puncture, can confirm the diagnosis and initiate life-saving treatment protocols.