For most people, headaches are a minor inconvenience.
Nearly all Americans have had at least one headache in their life, and half get one at least once a year.
Additionally, about 12 to 15 percent of the population – roughly 40 million people – suffers from migraines, which are severe, recurring headaches often accompanied by nausea, vomiting and extreme sensitivity to light and sound.
There are dozens of causes, ranging from poor posture to intense odors or sounds to dietary indulgences like red wine and chocolate.
In most cases, headaches and migraines can be beaten with over-the-counter pain medication, rest and other therapies like ice packs and heating pads. They also usually are not a sign of more serious, potentially life-threatening conditions.
However, in rare cases, there are life-threatening conditions that can manifest as intense, debilitating headaches, which require seeking immediate medical help.
Along with the severe pain, life-threatening conditions can also come with rapid blindness, dizziness and stiffness in the neck that radiates throughout the body.
Experts have revealed the four dangerous headache types that could be deadly without quick treatment.
Experts have revealed the four causes of headaches that could require immediate medical attention (stock image)
Acute angle-closure glaucoma
Acute angle-closure glaucoma (AACG) occurs when the iris – the colored, muscular part of the eye between the cornea and the front of the lens – suddenly bulges and blocks fluid in the eye from draining.
The fluid, called aqueous humor, is necessary for maintaining eye pressure and supporting the shape of the eye. If it’s blocked, intraocular pressure in the eye builds up.
‘This causes a rapid rise in intraocular pressure which can damage the optic nerve and even result in permanent vision loss,’ Jimmy Pang, a physical therapist in San Diego who specializes in headache and vestibular disorders, told the Daily Mail.
The eye’s natural lens thickens over time with aging and pushes against the iris, blocking drainage passages.
Being over 40 raises the risk, as well as having conditions like diabetes and high blood pressure, which damage tiny blood vessels that nourish the eye’s retina.
About one in 1,000 Americans suffer from AACG each year.
AACG comes on quickly, often within just a few hours, and leads to headache, severe eye pain, redness, vision loss, seeing rainbow-colored rings around lights or halos, nausea and vomiting.
AACG can be diagnosed with tests such as a gonioscopy, which assesses the eye’s drainage angle, and a slit-lamp exam, which uses a microscope to look inside the eye.
Prescription eye drops and a laser iridotomy, which makes a small hole in the eye to let fluid drain, can treat the condition but must be administered quickly to avoid permanent optic nerve damage.
Subarachnoid hemorrhage
Hemorrhages require immediate brain scans and surgery to avoid life-threatening consequences (stock image)
A subarachnoid hemorrhage is a form of stroke that occurs when there is bleeding in the space between the brain and protective tissues covering it, also known as the subarachnoid space.
The bleeding usually occurs when an irregular bulge in a blood vessel, called an aneurysm, bursts in the brain. Head injuries can raise the risk, as can something called an arteriovenous malformation, a tangle of blood vessels in the brain.
‘The key sign is when someone states that it is the worst headache of their life. That phrase alone means the patient needs to go to the emergency department,’ Pang said.
Nausea, vomiting, stiff neck, vision changes and brief losses of consciousness are also possible.
Recent studies estimate that 30,000 Americans experience a subarachnoid hemorrhage each year.
Subarachnoid hemorrhages that occur from burst aneurysms most often occur in people between ages 55 and 60 due to natural vascular weakening with age.
Connective tissue disorders such as Ehlers-Danlos syndrome and Marfan syndrome also weaken blood vessels and raise the risk of aneurysms.
A subarachnoid hemorrhage requires immediate medical attention and scans such as a CT and MRI to detect bleeding.
Surgery is usually required to place a clip in the aneurysm and stop blood flow.
Hypertensive intracerebral hemorrhage
Similar to subarachnoid hemorrhage, hypertensive intracerebral hemorrhage (HICH) is a life-threatening stroke caused by weakened deep brain arteries, which ultimately lead to rupture.
‘Hypertensive intracerebral hemorrhage is a brain bleed caused by the rupture of small arteries secondary to high blood pressure. It is considered a hemorrhagic stroke and is an emergency situation,’ Pang said.
HICH accounts for about 3 million cases globally each year, while high blood pressure affects nearly half the US population, or 120 million people.
Signs of HICH include a sudden, severe ‘thunderclap’ headache, along with nausea, vomiting and weakness or numbness.
Men over the age of 55 are at the greatest risk due to their vulnerability to uncontrolled high blood pressure.
Much like a subarachnoid hemorrhage, people who believe they are suffering from HICH need immediate CT and MRI scans and surgery to control the bleeding.
Cervicogenic headache
Cervicogenic headaches are often not serious, but they can affect blood flow and lead to brain injury (stock image)
Unlike many emergency headache cases, cervicogenic headaches don’t come on suddenly.
Instead, the pain develops gradually and is focused on the neck and upper portion of the spine. The pain presents as stiffness that then radiates to the back of the head.
Pain from this form of headache also can start at the back of the head and then radiate to the front, just behind the eyes.
Any injury or condition that affects the neck or spine can cause a cervicogenic headache, though it’s most often associated with fractures, arthritis, pinched nerves, slipped disks, sprained muscles and tumors pressing on the area.
While cervicogenic headaches can be harmless, major vessels that supply blood to the brain run close to the neck, and persistent tension could affect blood flow.
‘When there is damage to the arteries that supply the brain in the neck, we get reduced blood flow to the brain, which can result in anoxic brain injury,’ Pang said.
X-ray and MRI scans can detect damage to the neck, and physical therapy and medications can help manage neck stiffness.
Roughly two percent of Americans, or 6 million, report suffering from cervicogenic headaches.
