Cluster Headache

1 What is Cluster Headache?

Cluster headaches are severe headaches that occur in a cycle or clusters.

There are periods of intense headaches, followed by remission periods in which you do not have headaches.

Episodes of cluster headache, cluster periods, can persist for few weeks to months while remission periods may last for months to years.

Often referred to as one of the rare and most severe types of headache, the pain may awaken you from your sleep.

Usually, the pain is felt in or around one eye on one side of your head.

Medications may be used to reduce the duration, severity and frequency of attack.

2 Symptoms

The signs and symptoms of cluster headaches are:

  • Severe pain usually in or around one eye, may extend to face, head, neck, shoulders
  • Pain in one side (unilateral pain)
  • Restlessness
  • Overproduction of tears
  • Red swollen eye on the affected side
  • Blocked or runny nostril on affected side
  • Yellow and sweaty face
  • Sagging eyelid

Pain is unbearable. People with this condition say that the pain feels as if the eye is being pushed out of its socket. Pain causes restlessness and is aggravated by lying down. People may walk or sit during the attack. You may experience migraine-like symptoms, such as nausea, light and sound sensitivity.

A cluster period usually lasts for 6 to 12 weeks. The onset and length of each cluster period may be same from period to period. For instance, cluster periods may be experienced during a certain season, such as every spring.

Most people experience intermittent cluster headache where the cluster headache can last for a week to a year succeeded by remission period that can last up to a year before another attack occurs.

Chronic cluster period is characterized by continued cluster period for more than a year or remission period for less than a month:

  • Daily headaches, sometimes several times a day.
  • An attack that lasts for 15 minutes to 3 hours and recurs every 24 hours
  • Night attacks, generally 1 to 2 hours after you sleep
  • The pain stops suddenly in the same manner as it started
  • Exhaustion after pain

When to see a doctor?

Visit your doctor if you experience cluster headaches or your headache pattern changes. You doctor may recommend tests to rule out other medical condition, such as brain tumor or aneurysm (weakening of arterial walls). Visit your doctor immediately if you experience:

  • Sudden, sharp or piercing headache
  • Headache along with fever, nausea or vomiting, stiff neck, confusion, seizures, numbness, or difficulty speaking, which may indicate other serious problems like stroke, meningitis, encephalitis or brain tumor
  • Headache after an accident
  • An abrupt, intense “never-experienced before” pain
  • Headache that worsens with time and changes in pattern

3 Causes

The cause of cluster headache is not known. It may be caused due to abnormalities in hypothalamus.

Cluster attacks occur at the same time each day and during a certain season of the year, indicating involvement of body's biological clock in hypothalamus.

Any abnormality in the hypothalamus that maintains internal balance of your body, can cause consistent pattern of cluster headache.

Consuming alcohol after onset of cluster period can initiate unbearable headache. 

4 Making a Diagnosis

How to prepare yourself for the visit?

Your doctor can refer you to a neurologist (a specialist in nervous system disorders). Getting prepared for the visit can optimize the therapy and help make the visit more fruitful. Here is what you can do:
List out all the symptoms. Don’t miss the following details of your symptoms:

  • Date, time
  • Duration
  • Severity
  • Triggers
  • Symptoms before the headache, if any
  • Medications
  • Anything that provides relief

Write down your key medical information. Write down the names of all your medications, vitamins or supplements. Make a list of the questions to ask your doctor. Some typical questions can be:

  • What could be possible causes of my symptoms?
  • What types of tests do I need?
  • Is my condition likely temporary or chronic?
  • What are my treatment options and side effects of each option?
  • Do I need to see a specialist?

What your doctor wants to know?

Be well prepared to answer the questions your doctor is likely to ask:

  • When did you first notice symptoms and how severe are they?
  • Are your symptoms continuous or occasional?
  • Do your symptoms occur in a repetitive pattern such as occurring at the same time of day or during the same season each year?
  • Do your symptoms occur after you drink?
  • Does anything improve or aggravate your symptoms?

Cluster headache has unique pain and pattern of attack. Diagnosis can be differentiated by the type of pain, severity of your headache, incidence of headache, the part of brain affected by headache. If you have persistent headache, your doctor may recommend:

  • Neurological examination: Your doctor examines physical signs, if any. In some instances, your pupil may tend to be smaller or you may have sagging eyelids.
  • Imaging tests: Imaging tests like CT scan or MRI help to identify other causes of headache, such as, tumor or aneurysm.

5 Treatment

Treatment for cluster headache aims to avoid the attacks and reduce severity and duration of headache. Treating cluster headache can be tricky due to its abrupt onset and cessation. You need medications that act rapidly. Latest studies show these therapies are most effective for acute and preventive treatment:

Acute treatments

Treatments that act immediately are:


You may be administered 100% oxygen through a mask to relieve your pain. The effects are seen with 15 minutes. Though safe and inexpensive, this option is not always applicable because it is not possible to carry oxygen cylinder with you.


Injections of sumatriptan, a drug for migraine, can be given by your doctor. Nasal spray is also available which may provide the same relief. Sumatriptan should be avoided if you have high blood pressure or heart disease. Zolmitriptan, nasal spray or tablet, may be used if you cannot tolerate other fast acting medications.


Octreotide, synthetic analogue of the brain hormone somatostatin, can provide relief from cluster headache.

Local anesthetics

Local anesthetics, such as lidocaine, can reduce the pain.


Injectable dihydroergotamine may be effective for some people. It is not effective when inhaled.

Preventive treatments

These treatments are given as soon as the cluster period begins. The doses are gradually narrowed once the duration of cluster period ends.

Calcium channel blockers

Blood pressure drug verapamil is often the first line agent to avoid cluster headache. It is generally combined with other medications and are safe for long term use. Common side effects include: Constipation, nausea, extreme tiredness, swellings of the ankles and decrease in blood pressure.


Steroids such as prednisone provide rapid and significant relief. They are recommended if cluster headache has just begun or has short cluster period and long remission period. Long term use is not recommended as they may cause serious side effects like diabetes, high blood pressure, cataracts.

Lithium carbonate

This mood stabilizing drug is used when other medications fail to work. Doses may be adjusted to reduce side effects like tremor, increased thirst and diarrhea. Frequent blood tests are performed to monitor serious side effects, such as, kidney damage.

Nerve block

A combination of corticosteroid and anesthetic (numbing agent) is injected in the region around the occipital nerve, located at the back of your head.


Sublingual ergotamine tablets can be used to prevent nighttime attacks. You may also inject dihydroergotamine on your own. It is effective if taken as soon as cluster attack occurs. They can't be used together with triptans.


Some studies suggest that 10 milligrams of melatonin in the evening might decrease the incidence of cluster headache.
Other preventive medications that could be used for cluster headaches are anti-seizure medications such as divalproex and topiramate.


If your cluster headaches do not respond to medications or if you cannot tolerate the medications, you may consider surgery. The surgery attempts to damage the nerves that cause cluster headache and in most cases, the trigeminal nerve, that serves the area behind and around your eye, is the target. Surgery can cause complications, such as weakened jaw or numbing sensations in certain areas of your face and head.
Research in potential cluster headache treatments

Occipital nerve stimulation

Electrodes are placed in the back of your head and connected to generator (pacemaker-like device). The impulses from electrodes are sent to occipital nerve that may either block the pain pathway or relieve the pain signals. Occipital nerve stimulation may be effective in decreasing pain in some people with chronic cluster headaches.

Deep brain stimulation

Electrodes are placed in the hypothalamus, the part of your brain that causes pattern of cluster periods. A generator connected to electrodes can alter your brain's electrical impulses and provide relief. It may be effective in severe, chronic cluster headaches unresponsive to medications.

6 Prevention

Attack of cluster headache can't be prevented. However, preventive treatments can decrease the occurrence and severity of cluster headache.

You may be asked to avoid alcohol and nicotine to decrease the risk of attacks. 

7 Alternative and Homeopathic Remedies

A few alternative and homeopathic remedies exist for cluster headaches.

You may try alternative therapies like:

  • acupuncture,
  • acupressure,
  • therapeutic touch,
  • chiropractic
  • and homeopathy

but these therapies may provide no relief.

Melatonin may provide some relief in nighttime attacks.

8 Lifestyle and Coping

Following tips can help you cope better with the events of cluster attack:

  • Maintain a regular sleep routine. Cluster periods can be initiated by changes in your sleep schedule.
  • Avoid alcohol during cluster period.
  • Join support group.

9 Risks and Complications

Factors that increase the risk of having cluster headaches are:

  • Sex: Men are at higher risk of having cluster headaches than women.
  • Age: The condition can develop at any age. But, it is likely to develop between 20 and 50 years.
  • Smoking: Smoking increases the risk of cluster headaches.
  • Alcohol use: Alcohol can elicit an attack if you have risk of developing cluster headache.
  • Family history: If anyone in your family has cluster headache, your risk is higher.

10 Related Clinical Trials