Certain injuries and medical conditions can cause blurred vision and headache, but migraine is the most common cause.

Experiencing blurred vision and a headache at the same time can be frightening, especially the first time it happens.

Blurred vision can affect one or both eyes. It can cause your vision to be cloudy, dim, or even peppered with shapes and colors, making it difficult to see.

The following conditions can cause blurred vision and headaches at the same time.

Migraine is a headache disorder that affects over 39 million people in the United States. Of these individuals, 28 million are women. Migraine causes moderate to severe pain that’s often made worse by light, sound, or movement.

Blurred vision is one symptom that is sometimes part of a migraine aura, which is the name for the collection of symptoms that may precede a migraine by 10 to 30 minutes.

Other ocular symptoms of migraine aura include:

  • blind spots
  • temporary vision loss
  • seeing bright flashing lights

A migraine may typically last for several hours up to 3 to 4 days if left untreated. Common symptoms, in addition to headache pain, include nausea and vomiting and light sensitivity.

There is no cure for migraine. Your doctor can design a treatment plan that combines both preventive treatment and abortive measures, which means stopping a headache in progress.

Available treatment options might include:

  • medications
  • hormonal therapy
  • lifestyle changes
  • biofeedback
  • relaxation training
  • counseling
When to go to the ER or call 911

Go to the nearest emergency room or call 911 if you or someone else experiences a head injury or blurred vision and headache — especially if severe or sudden — with any of the following:

Sometimes blurry vision and headache can result from conditions that are medical emergencies and require immediate treatment. If you think you have any of these conditions, get medical attention quickly.

Headache with trauma

If a headache and blurry vision are a result of an injury, you may have a concussion, skull fracture, or other traumatic brain injury (TBI). Falls, motor vehicle accidents, and sports injuries are commonly cause TBI.

About 165 people in the United States die every day from injuries related to TBIs. Symptoms of TBI can range from mild to severe, depending on the extent of the damage. Other symptoms include:

New or severe headache without trauma

Some emergency conditions marked by headache and blurry vision can also occur without trauma. If you feel you have any of the following conditions, seek immediate medical help.

Closed-angle (acute) glaucoma

In closed-angle glaucoma, pressure in the eye builds up because fluid in the front part of the eye does not drain as it should. This is considered a medical emergency, and you should seek immediate medical attention.

If not treated, the pressure inside your eye can build to the point that it damages your optic nerve, which could result in permanent vision loss.

Closed-angle glaucoma is a rare form of glaucoma. Unlike the more common open-angle glaucoma, this type of glaucoma develops quickly, and its symptoms are obvious.

It is called closed-angle glaucoma because the angle between the iris and the cornea is either closed or very narrow. This most often occurs in older adults, especially those with smaller eyes.

Closed-angle glaucoma affects women about twice as often as men. Symptoms usually come on suddenly and can include:

  • blurred or hazy vision
  • head and eye pain
  • red eyes
  • nausea and vomiting
  • sudden sight loss

There is no cure for closed-angle glaucoma. Medications or surgery can slow the process down. Regular eye exams every 1 to 2 years can help catch it early so you can begin treatment.

Carbon monoxide poisoning

Carbon monoxide poisoning is an emergency that requires immediate medical care. It results from a buildup of carbon monoxide in your bloodstream.

Carbon monoxide (CO) is an odorless, colorless gas produced by burning wood, gas, propane, or other fuel.

In addition to blurred vision and headache, carbon monoxide poisoning may cause:

Carbon monoxide poisoning is treated with oxygen, either through a mask or placement in a hyperbaric oxygen chamber. Carbon monoxide poisoning is preventable. Be sure to have a functioning CO detector installed in your home.

Herpes zoster ophthalmicus (shingles in the eye)

The varicella zoster virus (VZV) that causes chicken pox also causes herpes zoster, or shingles. It can reactivate in people who have had chicken pox earlier in their life. When it does, it causes shingles.

When shingles affects the ophthalmic nerve, and ultimately the eye, it is called herpes zoster ophthalmicus, or shingles in the eye. It is considered a medical emergency because if it’s left untreated it can result in:

  • infection
  • chronic pain
  • vision loss

Early symptoms of herpes zoster opthalmicus may include:

  • headache
  • low fever
  • flu-like symptoms

Usually, within about a week, the hallmark symptom of shingles will appear — a painful rash with small blisters. With herpes zoster opthalmicus, the rash will appear in or around the eye, usually on one side of your face.

Your eye itself may be swollen, red, or puffy. Your eyelid, as well as the area around your eye, may be painful. Your vision will likely be affected, resulting in blurry or decreased vision. Although not common, herpes zoster opthalmicus is more likely to happen in women.

If you think you have shingles in the eye, get immediate medical treatment. Antiviral medications can usually clear the condition. Early treatment can help you avoid long-term complications.

Currently, there are vaccines available to help reduce the risk of getting shingles. Talk with your doctor about whether vaccination would help reduce your risk.

Meningitis and encephalitis

Meningitis and encephalitis are inflammatory diseases that affect the brain and spinal cord. Inflammation of the membranes that surround the brain and the spinal cord is called meningitis. Inflammation of the brain is encephalitis.

These are serious diseases caused by bacterial or viral infections, fungi, or parasites. People of any age can get these diseases, but those with compromised immune systems are at increased risk.

Fever and headache are the primary symptoms of both diseases, but double vision or blurry vision can also occur. In addition, symptoms could include nausea, vomiting, confusion, stiff neck (more so for meningitis), or seizures (more so for encephalitis).

Meningitis and encephalitis are medical emergencies, and you should seek medical attention immediately.

There are some vaccinations available to help prevent some types of meningitis. Talk with your doctor about whether vaccination would help reduce your risk.

Stroke

A stroke can cause blurred vision and a severe headache that comes on suddenly with no apparent cause. A transient ischemic attack (TIA), or mini-stroke, may also cause headache and blurred vision. Over 700,000 people in the United States have a stroke every year.

Other symptoms that often occur with a stroke include:

  • numbness or weakness of the arm, face, or leg, most often on just one side of the body
  • confusion
  • difficulty speaking or understanding others’ speech
  • trouble walking
  • coordination or balance difficulty

If you think you are having a stroke, get immediate medical attention. Time is crucial. Without prompt treatment, strokes may be life threatening or produce long-term disability.

Thunderclap headache

A thunderclap headache is a sudden severe headache that comes on strong and reaches its peak in less than a minute. It lasts about 5 minutes and may then go away. If you have one, get immediate medical attention.

One possible cause of a thunderclap headache is subarachnoid hemorrhage, or bleeding into the brain. This may result from a weak area in a blood vessel called an aneurysm.

The blood in a subarachnoid hemorrhage can build up inside the skull and increase pressure on the brain. Resulting brain cell damage can cause lifelong complications and disabilities.

Thunderclap headaches are uncommon. You may feel the pain in your head, neck, shoulder, or even in your back. Thunderclap headaches may also cause nausea and vomiting.

Thunderclap headaches seem to come out of nowhere, and their pain is intense. People often describe them as the worst headache of their lives.

This type of headache is considered an emergency because it can be caused by serious problems in your blood vessels or your brain structure.

Not all thunderclap headaches are serious. Some are benign and not dangerous. Their cause may never be determined. To be safe, always get immediate medical attention if you have a thunderclap headache.

Other concerning symptoms sometimes occur along with blurred vision and headache. If they do, especially in people who are older, they might point to further causes of your blurry vision and headache.

These additional symptoms might include:

  • increased pressure in the eye
  • dizziness or faintness
  • seizures
  • other neurological disorders
  • high blood pressure
  • headache at night

If these symptoms occur with blurred vision and headache, one of the following conditions might be the cause:

Eyestrain

Eyestrain, especially from overuse of digital screens, is very common. Headache and blurry vision are two of the most common symptoms. Other symptoms might include:

  • Strain or squinting to see
  • Dry eyes
  • Neck and shoulder pain

To avoid eyestrain, the American Optometric Association recommends following the 20-20-20 rule. This involves taking a 20-second break to view something 20 feet away every 20 minutes.

Other solutions to digital eyestrain involve having a good ergonomic seating position and avoiding light that produces glare on your screen. And of course, limit the amount of time you spend looking at screens.

Low blood sugar

Low blood sugar, or hypoglycemia, is when the level of glucose in the body drops below he optimum amount, which is between 70 and 110 mg/dL. Early symptoms may include:

  • headache
  • blurry vision
  • anxiety
  • irritability
  • shakiness
  • hunger

If the low blood sugar continues, later symptoms can include:

  • confusion
  • difficulty speaking
  • coma

It is important to realize that low blood sugar is a symptom of something, not a condition in itself. Common causes include medications for various conditions, especially diabetes, and heavy alcohol use.

Skipping meals, over-exercising, or extreme dieting can contribute to low blood sugar. Infection, severe heart, kidney, or liver failure can also cause it, although these are more rare.

A quick resolution of low blood sugar is to drink juice or eat food. Be sure to consult with your doctor if you have multiple instances of low blood sugar. Some of your medications may need to be adjusted.

Severe low blood sugar can come on suddenly, but usually it is gradual. It can occur most often in people with diabetes when their medication is not adjusted correctly. This can be a medical emergency.

If you are with someone who has diabetes and experiences even mild symptoms of low blood sugar, administer easily digestible carbohydrates like fruit juice, crackers, or candy, if the person is conscious.

An untreated episode of low blood sugar can lead to fainting, seizure, and even unconsciousness. Be sure to know the signs and be ready to get emergency medical attention when necessary.

Optic neuritis

When the eye’s optic nerve swells, it is called optic neuritis. The optic nerve is essential for your eyesight. It carries light signals from the back of your eye to your brain.

The optic nerve is what makes it possible for you to see. If it is swollen or damaged, you will not be able to see clearly.

The cause of optic neuritis is not known. It may be caused by a malfunctioning nervous system like from multiple sclerosis, or perhaps a viral infection like mumps or measles.

Symptoms include blurry or dim vision, and colors will look faded. You may experience pain in the back of your eye, or pain when you move your eyes. Symptoms may come on gradually or all of a sudden.

The usual treatment is corticosteroids. Prompt treatment may help stall your symptoms. In some cases, prompt treatment can even improve your sight to what it was before your optic neuritis.

Pheochromocytoma

Pheochromocytoma is a rare tumor, usually located in the adrenal glands. These are two glands located on the top of each of your kidneys.

Around 20-30 percent of pheochromocytomas are caused by genetic mutations that can be passed down in families. Diagnosis can sometimes be missed because symptoms mimic those of so many other conditions.

Symptoms usually happen in episodes. One of the primary symptoms is high blood pressure caused by hormones secreted by the tumor.

It is important to know that high blood pressure in itself does not cause blurry vision and headaches. In this case, it is associated with the blurry vision and headaches that are symptoms of pheochromocytoma.

Other common symptoms include:

  • headache
  • blurry vision
  • sweating
  • palpitations and other symptoms of a panic attack

Further symptoms might include:

  • anxiety
  • indigestion
  • nausea and vomiting
  • tremor
  • flushing
  • dizziness

The first-line treatment for pheochromocytoma is surgery to remove the tumor. Medications to lower blood pressure may be given before surgery. Usually, your blood pressure returns to normal after removal of the tumor.

Pseudotumor cerebri

Pseudotumor cerebri, also called idiopathic intracranial hypertension, is a condition of high pressure in the brain from increased cerebrospinal fluid. It’s most common in women of childbearing age who have obesity.

The pressure causes headaches that are usually felt at the back of the head and are worse at night or upon waking. It can also cause vision problems, such as blurred or double vision.

Other symptoms may include:

  • dizziness
  • persistent ringing in the ears
  • depression
  • nausea and/or vomiting

Prompt medical attention is required for pseudotumor cerebri, especially if you’re experiencing visual disturbances. Early treatment could help prevent permanent vision loss.

Temporal arteritis

Temporal arteritis, also called giant cell arteritis, is an inflammation of the temporal arteries. These are the blood vessels near the temples. They supply blood from your heart to your scalp.

When these arteries become inflamed, they restrict blood flow, which can cause permanent damage to your eyesight.

This condition is most common in individuals over 50, particularly women.

A throbbing, persistent headache on one or both sides of your head is the most common symptom. Blurred vision or brief vision loss is also common.

Other symptoms may include:

  • jaw pain that worsens with chewing
  • scalp or temple tenderness
  • muscle aches
  • fatigue
  • fever

Prompt medical attention is required for temporal arteritis, especially if you are experiencing visual disturbances. Early treatment could help prevent permanent vision loss.

Diagnosing the cause of blurred vision and headache may require a review of your medical history and a number of different tests. These tests may include:

Depending on your situation, a specialist like a neurologist or neurosurgeon may be consulted for further evaluation and guidance on treatment.

Treatment will depend on the cause of your blurred vision and headache. Each condition will involve different medications and treatment regimens.

In cases involving emergency conditions, your first responsibility is to get medical attention as quickly as possible. Your medical team will then be able to advise you of treatment options.

Your doctor will choose tests to diagnose conditions quickly that require emergency care or urgent care so that treatment can be started. They will then decide on further evaluations and treatments.

Blurred vision and headache together can indicate a serious medical condition. For emergency conditions, you should get medical attention immediately.

For other conditions, talk with your doctor about a recommended consultation and treatment. You will usually need a doctor’s visit to rule out a serious condition and get a diagnosis for treatment.

If your symptoms are mild and only last for a short period of time, or if you’ve been diagnosed with migraine, be sure to tell your doctor.

Blurred vision and headache are most often caused by migraine, but they can also be caused by other serious conditions. If you’re concerned about your symptoms, make an appointment with your doctor.

If your symptoms began after a head injury, are sudden and severe, or accompanied by symptoms of a stroke, such as difficulty speaking and confusion, seek immediate emergency medical care.