Increased Intracranial Pressure (ICP) Headache: Causes, Symptoms, Diagnosis, and Treatment

Understand the warning signs, causes, diagnosis, and urgent care needed for headaches linked to increased intracranial pressure.

By Medha deb

Created on Oct 3, 2025

Understand the warning signs, causes, diagnosis, and urgent care needed for headaches linked to increased intracranial pressure.

Increased Intracranial Pressure (ICP) Headache

Increased intracranial pressure (ICP) is a serious medical condition where the pressure inside the skull rises, which can have critical effects on the brain and spinal cord. Headaches linked with increased ICP demand immediate medical attention, as the underlying causes are often life-threatening and rapid treatment is crucial for the best possible outcome.

What Is Increased Intracranial Pressure?

Intracranial pressure (ICP) refers to the pressure exerted by fluids such as cerebrospinal fluid (CSF) and blood within the skull on brain tissue. When ICP rises above normal levels, it can endanger brain function and threaten life. Increased ICP can arise from illnesses, injuries, or unknown causes, and often causes distinctive types of headaches and neurological symptoms.

Normal ICP is usually between 5 and 15 mmHg.
Pressures above 20 mmHg are considered abnormal and may require intervention.
Rapid or sustained rises in ICP can damage delicate brain tissue and compromise vital functions.

Why Is Increased ICP an Emergency?

An urgent medical response is necessary when increased ICP is suspected. The brain is encased in the rigid skull, so any increase in pressure leaves little room for expansion, leading to compression of brain structures.

Increased ICP can restrict blood supply to the brain, causing irreversible damage.
This condition can quickly escalate and may cause herniation—a potentially fatal shifting of brain tissue.
Immediate assessment, diagnosis, and management can improve the chances for recovery and prevent long-term neurological disability or death.

Causes of Increased Intracranial Pressure

Many medical conditions and injuries can lead to increased ICP. Understanding these causes helps clinicians determine the best course of action for treatment.

Brain tumors or masses: Growth of benign or malignant tumors increases internal volume.
Head injuries: Any trauma causing bleeding, swelling, or bruising within the skull.
Hemorrhage or bleeding:

Subarachnoid hemorrhage
Epidural or subdural hematomas
Intraventricular hemorrhage
Hypertensive brain hemorrhage

Hydrocephalus: Abnormal buildup of CSF due to blocked or impaired drainage.
Infections:

Meningitis
Encephalitis
Brain abscess

Stroke: Swelling or bleeding into the brain can increase pressure.
Venous sinus thrombosis: Blood clots in the veins draining the brain impede outflow and cause congestion.
Idiopathic Intracranial Hypertension (IIH): Increased ICP without an identifiable cause, often seen in young, overweight women.
Other causes:

Brain aneurysm rupture
High blood pressure
Seizures
Brain injury after cardiac arrest
Certain metabolic or toxic disorders

Symptoms of Increased ICP

The classic symptoms of increased ICP can vary depending on the cause, the underlying medical condition, and the speed at which pressure builds. However, some symptoms are especially characteristic of this condition.

Headache: Typically intense, throbbing, worse in the morning or when lying flat. May intensify during coughing, straining, or sudden movement.
Nausea and vomiting: Often accompanies headache and may be sudden and severe.
Visual disturbances:

Blurred or double vision
Brief episodes of visual blackout or loss (especially with positional changes)
Loss of peripheral vision

Altered mental status:

Confusion
Behavioral changes—irritability, restlessness, or lethargy
Drowsiness progressing to coma in severe cases

Motor and speech dysfunction:

Weakness or difficulty moving
Problems speaking clearly

Seizures: Especially if pressure rises quickly.
Other neurological deficits:

Bilateral ptosis (drooping eyelids)
Impaired upward gaze
Pupil changes—dilated or unresponsive pupils

Cushing’s triad (ominous sign):

High blood pressure
Slow heart rate (bradycardia)
Irregular respirations

Coma can develop if not treated promptly.

ICP Headache in Children vs. Adults

Signs and symptoms of increased ICP may present differently in children, especially infants and younger toddlers. Key differences include:

Infants may develop a bulging soft spot (fontanelle) on the head.
Persistent vomiting
Inconsolable crying and high-pitched screams may occur.
In older children, symptoms may resemble those in adults, but behavioral changes and irritability can be more prominent.

How Is Increased Intracranial Pressure Diagnosed?

Rapid and accurate diagnosis of increased ICP is critical for initiating life-saving treatment. Assessment is conducted in the emergency or hospital setting through a combination of medical history, clinical examination, and specialized testing.

Medical history and symptom review: Onset, progression, and character of symptoms provide early clues.
Neurological examination: Evaluates mental state, movement, speech, reflexes, pupillary responses, and eye movements.
Fundoscopic (eye) examination: Helps detect papilledema, which is swelling of the optic nerve head due to increased pressure.
Imaging studies:

CT (computed tomography) scan: Quickly reveals bleeding, masses, swelling, and other structural abnormalities.
MRI (magnetic resonance imaging): Provides detailed images and may clarify subtle or complex problems.

Measurement of ICP:

Direct measurement is possible in intensive care through placement of an ICP monitor (intraventricular catheter or other device).

Lumbar puncture (spinal tap):

Measures cerebrospinal fluid pressure and analyzes fluid for signs of infection, inflammation, or other abnormalities.
Important: Lumbar puncture should only be done after imaging to exclude mass effect, which would make the procedure dangerous.

Laboratory studies: Identify infection, clotting problems, metabolic issues, or toxins that could be contributing.

How Is Increased Intracranial Pressure Treated?

Treatment for increased ICP focuses first on rapidly lowering pressure to prevent brain damage and then on addressing the underlying cause.

Emergency Measures

Positioning: Elevate the head of the bed to 30 degrees to encourage drainage of venous blood and CSF from the brain.
Oxygen therapy: Ensures adequate oxygenation to brain tissue.
Medications:

Diuretics (e.g., mannitol, hypertonic saline) to draw fluid out of the brain and decrease pressure.
Steroids to reduce swelling (mainly in cases of tumors or inflammation).
Anti-seizure medications if seizures present.

Strict monitoring: Frequent neurologic checks and continuous measurement of vital signs.
ICP monitoring: May involve a catheter or sensor placed in the brain to track pressure and guide therapy.

Definitive Treatments

Surgical intervention:

Removal of tumors or blood clots.
Draining CSF via an external ventricular drain or shunt system to relieve pressure in cases like hydrocephalus.
Decompressive craniectomy: Removal of part of the skull to allow brain swelling without serious compression (used in refractory cases).

Treatment of infection with antibiotics or antiviral drugs where necessary.
Management of underlying causes such as controlling high blood pressure, treating blood clots, or managing a metabolic disorder.

What Happens If Increased ICP Is Left Untreated?

Failure to treat increased ICP promptly can result in devastating consequences, including permanent brain injury, loss of vision, physical disability, and death. Herniation syndromes caused by compression can rapidly become fatal.

Prevention and Risk Factors

Some causes of increased ICP are preventable or manageable by addressing risk factors.

Prompt treatment of infections and head injuries.
Careful management of chronic diseases like high blood pressure.
Regular follow-up for known brain tumors or structural lesions.
Weight management—especially important in idiopathic intracranial hypertension.

Living With Increased ICP or After Recovery

Recovery from increased ICP can vary. Some patients make a full recovery, especially if treated quickly, while others may be left with lasting neurological effects, including physical or cognitive changes. Close monitoring, rehabilitation, and long-term care may be necessary for some individuals.

Regular medical follow-up and imaging may be needed.
Ongoing medication to prevent recurrence (for example, in IIH or hydrocephalus).
Support for physical, occupational, or speech therapy as needed.

Frequently Asked Questions (FAQs) About Increased ICP Headache

What should I do if I think I have symptoms of increased ICP?

Seek emergency medical care if you experience a sudden, severe headache with vomiting, changes in vision, confusion, seizures, or weakness.

Can increased ICP cause permanent damage?

Yes, untreated increased ICP can cause permanent brain injury, vision loss, disability, or death. Prompt intervention is key.

How is increased ICP different from a typical headache?

ICP headaches are severe, often worsen with movement, and are linked with neurological symptoms like vomiting, confusion, or vision loss—features not typical of a simple tension-type or migraine headache.

Is there a way to prevent increased ICP?

Prevention focuses on managing underlying risk factors, such as infection control, injury prevention, and treatment of chronic medical conditions. Some causes, such as tumors or idiopathic cases, are not always preventable.

What is idiopathic intracranial hypertension?

Idiopathic intracranial hypertension (IIH) refers to increased ICP with no identifiable underlying cause, often seen in overweight women of childbearing age. It requires careful diagnosis and management to prevent vision loss and other complications.

When to Seek Medical Attention

If you or someone you know experiences the concerning symptoms described above—especially a sudden, severe headache with vomiting, loss of consciousness, or vision changes—immediate medical attention is critical. Early recognition and prompt, expert care save lives and reduce the potential for long-term effects.

References

Author

medha deb

Medha Deb is an editor with a master's degree in Applied Linguistics from the University of Hyderabad. She believes that her qualification has helped her develop a deep understanding of language and its application in various contexts.

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