Feeling pressure in your head is a common headache symptom. But a "pressure headache" is not really a headache type. Ironically, that feeling of pressure almost always stems from muscle tension outside your head.
That said, a headache can be caused by an increase of pressure inside your head, although that's rare. If it does occur, however, it can be a dangerous situation.
Pressure From the Outside
"Both migraine and tension headaches can have pressure symptoms," says Zubair Ahmed, MD, a neurologist and headache specialist at Cleveland Clinic Center for Neuro-Restoration in Cleveland, Ohio. "Migraine has pulsating pain on one side of the head that can feel like pressure. Tension headache has squeezing pressure on both sides of the head." However, he notes, "neither of these symptoms is actually caused by increased intracranial pressure."
Tension headaches are the most common type of headache, affecting about three of every four adults. If you have this type of headache, it might feel like your head is in a vice, according to Harvard Health.
Migraine headaches are the next most common type, affecting more than one in 10 people. The throbbing pain is more severe than with a tension headache and can also be described as intense pressure. In a migraine headache, the pain is coming from sensitive blood vessels inside your brain, but brain pressure does not change, states Harvard Health.
Increased Intracranial Pressure
When the pressure you're feeling is truly coming from within your head, it's called increased intracranial pressure (ICP). As a cause of headache, it's much less common than tension and migraine headaches but extremely dangerous.
"An ICP headache is what we call 'a red-flag headache,'" Dr. Ahmed says. "These headaches can be severe and relentless. They don't come and go. They get progressively worse. They may be affected by position changes and may affect your vision. Red-flag headaches always need medical attention to find the cause."
Normally, your brain and spinal cord — your central nervous system — is bathed in a nourishing and protective fluid called cerebrospinal fluid. The pressure of this fluid should stay constant. If the pressure goes up, ICP occurs. According to Johns Hopkins Medicine, causes can include:
- Too much cerebrospinal fluid (hydrocephalus)
- Bleeding into the brain
- Swelling of the brain from infection or injury
- A brain tumor
- A ballooning blood vessel (aneurysm)
- Intracranial hypertension
Headache from an aneurysm can feel like a migraine. The affected blood vessel in the brain can rupture and bleed into the brain, causing a stroke.
Headache from a tumor gets progressively worse. Symptoms from a tumor can include projectile vomiting, visual changes, changes in speech, loss of balance and seizures, according to the National Headache Foundation.
Intracranial hypertension (IH) is another cause of intense headaches from pressure inside your central nervous system. About 90 percent of people with this condition have very painful headaches that are not relieved by migraine or other headache medications. Other symptoms include hearing a pulsing sound in the ears and visual changes. This headache may last for days or weeks. Doing a spinal tap to lower pressure in the brain and spinal cord will relieve the headache, according to Intracranial Hypertension Research Foundation.
These are the common red flag warnings for most types of ICP headache, according to Johns Hopkins:
- Severe headache
- Any sudden change in vision or speech
- Changes in behavior
- Projectile vomiting
- Weakness or loss of balance
- Extreme pain when lying down or bending over
If you have any of these symptoms, get medical attention right away. Particularly if you have a very sudden, very severe headache that you would describe as the worst headache you've ever had, call 911 or be taken to an emergency room.
The cause of ICP can often be diagnosed with a spinal tap and a brain imaging study. Treatment will depend on the cause, but the sooner you get a diagnosis, the more successful the treatment will be.
Read more: How to Relieve a Headache in 10 Minutes