What are cluster headaches?

Cluster headaches can be very painful. They occur several times a day, start suddenly, and last for a limited time. The exact cause of cluster headaches remains unknown, though there are several theories.

Cluster headaches occur cyclically. A bout of regular attacks, known as a cluster period, can last a few days, weeks, or months. During remission periods, a person has no headaches.

Cluster headaches are not common, affecting about 1 in 1,000Trusted Source people. Six out of 10 cases involve men, and most of these are people who smoke. The headaches usually start after the age of 20.

Keep reading to learn more about cluster headaches, including the symptoms, causes, and treatment methods.

Symptoms of Cluster Headaches

These are some of the symptoms of cluster headaches:

• A sudden burning or piercing pain 
• Pain around or behind one eye, that may also spread to the forehead, nose, temple, jaw, or neck on that side of the face
• Redness, watering, or pain in the affected eye
• Smaller pupil size in the affected eye
• Swollen or droopy eyelids
• Stuffy or runny nose, particularly on the side of the head that hurts
• Flushed face or excessive sweating
• Agitation or restlessness, that may be characterized by pacing or rocking rather than sitting or lying down while the headache is ongoing

Each headache can last anywhere between 15 minutes and three hours. The pain usually reaches its peak intensity within five or 10 minutes.

Cluster headaches typically develop a pattern and appear at the same time or in the same manner, sometimes for weeks or months at a time. A period of cluster headaches can be followed by a period of remission, without any headaches for months or years.

Some people experience cluster headaches at night, after going to bed—these nighttime headaches can feel even more severe than headaches experienced during the day.

Causes of Cluster Headaches

The pain from cluster headaches is caused by the dilation, or widening, of the blood vessels that supply blood to your brain and face. This dilation applies pressure to the trigeminal nerve, which transmits sensations from the face to the brain. It is unknown why this dilation occurs.

Researchers believe that abnormalities in the hypothalamus, a small area of the brain that regulates body temperature, blood pressure, sleep, and the release of hormones, may be responsible for cluster headaches.

Cluster headaches may also be caused by a sudden release of the chemicals histamine, which fight allergens, or serotonin, which regulates mood.

Diagnosed of Cluster Headaches

Your doctor will ask you questions about your symptoms and give you a physical and neurological exam. This may include an MRI or CT scan of your brain to rule out other causes of the headaches, such as a brain tumor.

Distinguishing a Cluster Headache from Other Types of Headaches

Cluster headaches usually start suddenly. A small percentage of people experience aura-like visual disturbances, such as flashes of light, before headaches begin.

Most commonly, headaches begin a few hours after you fall asleep and are often painful enough to wake you, but they may also begin when you are awake.

Headache pain becomes severe 5-10 minutes after the headache starts. Each headache usually lasts for several hours, with the most intense pain lasting between 30 minutes and 2 hours.

Cluster headache pain occurs on one side of the head, but can switch sides in some people, and is generally located behind or around the eye. It is described as a constant and deep burning or piercing pain. People with this pain say it is like a hot poker being stuck into your eye. The pain may spread to the forehead, temples, teeth, nose, neck, or shoulders on the same side.

Other signs and symptoms may be evident on the painful side of the head, including:

• a droopy eyelid
• a constricted pupil
• excessive tearing from your eye
• eye redness
• sensitivity to light
• swelling under or around one or both of your eyes
• a runny nose or stuffy nose
• facial redness or flushing
• nausea
• agitation or restlessness

Cluster headaches or migraine?

Cluster headaches and migraine are both severe forms of headache, but they are different and need specific treatments.

Before a migraine headache, a person will typically experience an “aura,” or visual disturbances, including flashing lights or zigzag lines. Migraine can last for up to 72 hours, and commonly involves nausea, vomiting, and sensitivity to light.

A cluster headache starts and ends suddenly, and it lasts a shorter time. It can feature congestion, watery eyes, and a runny nose. It normally affects only one side of the head, and the eye that is watering is on the same side.

A person with migraine prefers to lie down during an attack, but people with cluster headaches may find that lying down worsens the pain.

Treating Cluster Headaches

Over-the-counter pain medication or narcotic painkillers may not help with cluster headaches as they can take time to provide relief. Therefore, it’s important to see a specialist for treatment options. 

Treatment generally focuses on providing relief for cluster headaches once they start, and preventing future headaches.

These are some of the treatments that can help with cluster headaches:

• Injections or nasal sprays: Your healthcare provider may give you an injection or a nasal spray of medicines such as sumatriptan, zolmitriptan, or dihydroergotamine, for rapid relief from an ongoing headache.
• Oxygen therapy: Breathing in pure oxygen through a face mask can also help relieve an ongoing headache.
• Other medication: Other types of medicines, such as allergy medication, blood pressure medication, antidepressants, anti-inflammatory medication and seizure medication may help prevent and treat cluster headaches.
• Physical therapies: Physiotherapy, acupuncture, and chiropractic adjustment are physical therapy options that may help with the headaches.
• Surgery: If other treatments are not helping, your healthcare provider may suggest surgically implanting a neurostimulator into your body. A neurostimulator is a device that delivers tiny electrical signals to your nerves.

You may need more than one type of treatment to treat your headaches. You may have to try different types of medications before your healthcare provider is able to determine which one works best for you.

Possible future treatments

Some new treatment options under investigation includeTrusted Source:

• Occipital nerve stimulation: This involves implanting a small device over the occipital nerve. It sends impulses via electrodes.
• Deep brain stimulation: This involves implanting a stimulator in the hypothalamus to change the electrical impulses in the brain.

Preventing Cluster Headaches

These are some steps you can take to prevent cluster headaches.

Avoid Triggers

If you’re prone to cluster headaches, it may be helpful to avoid smoking and drinking alcohol. Additionally, if you’ve identified any foods or other factors that trigger your headaches, it’s best to avoid those as much as possible.

Maintain a Headache Diary

Maintain a journal where you note down the details of your headaches, to help you and your healthcare provider identify patterns and triggers.

For each instance, include information about: 

• Which parts of your head hurt 
• How intense the pain is
• What time the headache started
• How long the headache lasted
• How long it’s been since your last headache
• What you ate and drank that day
• How much sleep you got the night before
• Where you were and what you were doing when the pain started
• What made the headache stop

Risk factors

Risk factors for cluster headaches includeTrusted Source:

• being male
• being older than 30
• drinking alcohol
• prior experience of brain surgery or trauma
• family history of cluster headaches or migraine headaches

Anyone who has regular headaches should see a doctor. Treatment can relieve symptoms, and it may be necessary to rule out any possible underlying causes.

Vagus nerve stimulation may also be effective.

Summary

Cluster headaches are painful headaches that can occur several times a day. Episodes typically come in cycles and may occur around the same time each year.

The symptoms of cluster headaches include sharp, stabbing pain on one side of the head. There can also be restlessness, nasal congestion, and pale skin.

There is currently no cure for cluster headaches. However, people can take a combination of short- and long-term medications to reduce the frequency and severity of episodes.