Cluster headache

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at June 19, 2016
StartDiseasesCluster headache

Cluster headaches are some of the most painful types of headaches a person can experience. Someone suffering from cluster headaches can have several attacks each day. Fortunately, cluster headaches are rare, and treatments are available to reduce their severity. 


Definition & Facts

Cluster headaches refer to headaches that recur over a period of time. Individuals who have cluster headaches will experience a headache one to three times each day during a period of time known as a cluster period. A cluster period can last from weeks to months. While cluster headache attacks can be more intense than migraine attacks, they don't last as long. Oftentimes, people will go into remission where the cluster headaches will disappear for months or years at a time before reappearing. 

Symptoms & Complaints

Cluster headaches typically occur without warning. During an attack, a person feels excruciating pain on one side of the face, usually in or around one eye. However, the pain may radiate to other parts of the face, such as the temple, forehead, cheek, or upper gum on the affected side. The pain may also radiate to the neck or shoulders. People with this type of headache describe the pain they feel as sharp or burning

During a cluster headache, someone may also experience excessive tearing and redness in the affected eye and a runny nose or stuffy nasal passage in the affected nostril. A drooping eyelid and swelling around the eye on the affected side of the face may also occur. Sweaty pale skin on the face may also be seen during an attack.

During an attack, people with cluster headaches tend to be restless. Unlike people with migraines, those with cluster headaches tend to avoid laying down because this position often increases the pain. The pain from these headaches lasts from 15 minutes to three hours, and people with this condition have one or more attacks each day during a cluster period. The pain subsides as quickly as it occurs. The attacks typically occur around the same time each day. Many attacks happen at night, generally one to two hours after the patient falls asleep. 

Most people with the condition suffer from episodic cluster headaches. In episodic cluster headaches, the headaches last from one week to one year, followed by a pain-free remission period that can last up to one year in duration before another cluster headache occurs. 

Other people with this condition have chronic cluster headaches. When a person experiences chronic cluster headaches, the headaches may last for more than one year or pain-free remission periods may last less than one month in duration. 


Unlike tension or migraine headaches, cluster headaches typically aren't associated with triggers. However, once a cluster period has begun, the consumption of alcohol can quickly lead to an excruciating headache. For this reason, many individuals will avoid consuming any alcohol during cluster periods. 

The exact cause of cluster headaches isn't known. Abnormalities in the hypothalamus may play a role in this condition. Cluster headaches typically occur with regularity during a 24-hour day. Additionally, cluster periods tend to follow the seasons of the year. These patterns indicate the involvement of the body's biological clock, which is located in the hypothalamus.

The hypothalamus is a part of the brain that is responsible for many functions, including regulating a person's sleep and wake schedules. Imaging studies have shown increased activity in the hypothalamus at the start of a cluster headache. 

There are some risk factors for developing cluster headaches. For instance, a family history of cluster headaches may put an individual at increased risk of developing the condition. Men are more likely than women to get cluster headaches. While cluster headaches can develop at any age, most people start suffering from the condition between the ages of 20 and 50. Smoking may also increase a person's risk for developing the condition.

Diagnosis & Tests

A diagnosis of cluster headaches is made based upon a person's description of her symptoms and the severity and location of the pain. A doctor may perform a neurological examination to look for physical signs of cluster headaches, such as a drooping eyelid or a small pupil, which may be present even outside of an attack.

Additionally, a doctor may order imaging tests to rule out other serious causes of headaches, such as an aneurysm or a tumor. Common imaging tests that may be ordered include a computerized tomography (CT) scan and a magnetic resonance imaging (MRI) test.

Treatment & Therapy

While there is no cure for this condition, treatment options are available. Treatment is designed to decrease pain, shorten headaches, and prevent attacks. Inhaling 100% oxygen for a brief period of time has been shown to be successful for reducing the pain of cluster headaches. The treatment is safe and inexpensive, but many people find it cumbersome to carry an oxygen cylinder and mask with them. 

A class of medications called triptans have also been shown to be effective for relieving acute cluster headaches. Sumatriptan, a medication commonly utilized in the treatment of migraine headaches, is also effective in relieving acute cluster headaches. Sumatriptan can be given by injection or taken as a nasal spray. However, sumatriptan in injection form tends to work faster and more effectively than sumatriptan nasal spray. People who have heart disease or high blood pressure should not use sumatriptan. 

Zolmitriptan is an alternative triptan medication that is effective for the treatment of cluster headaches. Zolmitriptan can be taken in nasal spray or tablet form. It may be a good option for patients who cannot take sumatriptan. 

When given through the nose, a local anesthetic, such as lidocaine, may be effective in treating the severe pain of these headaches as well. Octreotide, an injectable synthetic form of the hormone somatostatin, is also an effective treatment option. 

Dihydroergotamine given intravenously is another effective treatment option for acute cluster headaches. The drawback to this treatment option is that patients must get the medication injected intravenously at a doctor's office or hospital.

Other medications can be utilized to suppress cluster headaches once a cluster period has begun. Calcium channel blockers, such as varapamil are often the first choice for the prevention of attacks. Calcium channel blockers may be used in conjunction with other medications to help manage attacks. Calcium channel blockers may need to be used on a long-term basis to help manage chronic cluster headaches. 

An occipital nerve block, where an anesthetic and corticosteroid are injected into the back of the head, may be an effective treatment option for chronic cluster headache sufferers as well. An occipital nerve block may also be effective at temporarily relieving pain while other preventive medications take effect. 

Lithium carbonate, a medication used in the treatment of bipolar disorder, may also be used to treat cluster headaches when other preventive medications have not been effective. Side effects of lithium carbonate include diarrhea, increased thirst, and tremor. Patients who take this medication must have their blood tested regularly to check for more serious side effects, such as kidney failure as well. Finally, research indicates that taking melatonin in the evening may help reduce the frequency of cluster headache attacks. 

Surgery for chronic cluster headaches is a last resort and rarely recommended. The goal of surgery is to damage the nerve pathways thought to be responsible for producing the pain, most commonly the trigeminal nerve. The trigeminal nerve deals with the area behind and around the eye. The long-term benefits of surgery are debated. Possible complications of surgery include sensory loss in certain parts of the face and head and muscle weakness in the jaw

Prevention & Prophylaxis

Preventing the initial onset of cluster headaches is not possible because the exact cause of the condition isn't yet known. However, certain medications including verapamil and topiramate can be used successfully to reduce the severity, duration, and frequency of the attacks. Preventive medications can also increase the effectiveness of medications used to treat acute cluster headaches.