Sentinel Headache

A sentinel headache is a consequence of minor blood leakage in the brain. Sometimes referred to as a “warning leak,” a sentinel headache may occur a few hours or several weeks before a subarachnoid hemorrhage—bleeding in the space around the brain that usually results from an aneurysm, or a weak area of a blood vessel that ruptures. A subarachnoid hemorrhage is a life-threatening condition that requires immediate medical treatment.

Tampa General Hospital’s Neuroscience Institute is the most active hospital in the region and excels in addressing sentinel headaches, subarachnoid hemorrhages and other complex neurological conditions. Featuring applauded specialists who put clinical breakthroughs into everyday practice, TGH features a neuroscience intensive care unit that’s one of the largest in the country. We’ve also earned the “high performing” distinction from U.S. News & World Report for 2024-25, meaning we rank among the top 10% of hospitals nationwide for Neurology & Neurosurgery.

Sentinel Headache Causes

There’s still much to learn about the specific causes of sentinel headaches. Generally speaking, though, bleeding in the brain can result from: 

  • Head trauma
  • Aneurysms
  • High blood pressure (hypertension)
  • Brain tumors
  • Vascular abnormalities, such as poorly connected veins and arteries

Symptoms of a Sentinel Headache

A sentinel headache is characterized by sudden, severe head pain. Many people describe this headache—sometimes called a “thunderclap” headache (TCH)—as the worst they’ve ever experienced. The pain usually peaks within five minutes, persists for at least one hour and may be accompanied by:

  • Nausea or vomiting
  • General malaise
  • Sensitivity to light
  • Neck pain

Diagnosing a Sentinel Headache

Unlike a typical headache that results from everyday factors like too much screen time or not drinking enough water, a sentinel headache triggers more intense symptoms that will typically cause someone to seek immediate medical care. To understand what’s causing the headache, a physician will likely perform imaging tests to view detailed pictures of the brain, such as magnetic resonance imaging (MRI) or a computed tomography (CT) scan. Blood tests, an electroencephalogram or a spinal tap may also be performed to gather additional information and make a diagnosis.

Sentinel Headache Treatment

Treatment for a sentinel headache will depend on its underlying cause. Generally speaking, bleeding in the brain requires emergency treatment to identify the source of the bleeding and release built-up pressure caused by pooled blood. If a sentinel headache exposes an aneurysm risk, a procedure to prevent rupture by sealing off the weak part of the blood vessel may be performed.

Choose TGH

Multifaceted neurological issues like sentinel headaches require the expertise of highly experienced specialists, such as those at TGH’s Neuroscience Institute. Contact us at (800) 822-3627 to learn about physician referrals or to schedule an appointment. You can also use our Find a Doctor database to find a neurologist.