In this article, we will look at what cluster headaches might be, their diagnosis and treatment. We will also look at any risk factors and the chronology (timing) of these disruptive events.
Contents of this article:
Fast facts on cluster headaches
Here are some key points about cluster headaches. More detail and supporting information is in the main article.
- Cluster headaches normally affect one side of the head and the area around the eyes
- In northern countries, cluster headaches occur most frequently during the fall
- Cluster headaches affect around 1 in 1,000 people
- An average cluster lasts for around an hour
- Other than pain, symptoms can include a reddened eye on the affected side of the head and a stuffy nose
- Sufferers often find it hard to sit still during an attack; they may pace around
- The pain often appears almost instantly and disappears the same way
- Around 80% of people who experience cluster headaches are male
- Black people are twice as likely to experience cluster headaches as white people.
What is a cluster headache?
Cluster headaches most generally affect just one side of the head at a time.
A cluster-headache sufferer can wake up during the night because of the pain. Often, this occurs at the same time each night.
The eye on the painful side of the head may be reddened and watery. The individual's nose may be runny or blocked on the side of the nose where the pain is.
In northern countries cluster headaches tend to occur more frequently during the autumn (fall) and spring. Alcohol or extreme variations in temperature can trigger an episode during a cluster period - generally, the change in temperature refers to a rapid rise in body temperature.
Cluster headache attacks occur cyclically, hence the name. A bout of regular attacks - cluster periods - can last from a few days, weeks, to even months. This is followed by remission periods during which no headaches are felt.
Cluster headaches are not very common - they are said to affect about 1 in every 1,000 people. They affect men more often than women; about 80% of sufferers are men, most of them smokers. Fortunately, they generally have no long-term effects on the sufferer's physical health. There are drugs, such as sumatriptan, and therapies, such as oxygen therapy, available which can significantly reduce the number and intensities of headaches.
Each cluster can last from 15 minutes up to several hours - the majority of cases do not last more than an hour. Typically, a patient will suffer from one to three clusters each day.
Symptoms of cluster headachesSymptoms come on rapidly, generally without any warning.
Symptoms of cluster headaches include:
- Intense pain, some describe it as excruciating. The pain is continuous, rather than throbbing. The pain often starts around the eye, and may then radiate to other parts of the head, including the face, and down to the neck and even the shoulders. Many patients feel pain in a temple or cheek.
- The pain remains on one side of the head
- The patient becomes restless.
- The eye on the side of the pain is watery and tearful
- The eye on the side of the pain reddens
- There may be swelling around the eye on the pain side
- Stuffy, blocked, or runny nose on the pain side
- Pallor - skin of the face is pale
- Face is sometimes sweaty
- Pupil size may shrink
- Eyelid on the pain side may droop.
While migraine sufferers prefer to lie down during an attack, people with a cluster headaches say that lying down worsens the pain.
Chronology (timing) of cluster headachesA cluster period typically lasts from 1 to 12 weeks. They often start at similar calendar moments - perhaps during springtime or at some time in the fall (autumn).
- Episodic cluster headaches - patients experience a series of searing headaches for about one week. Then nothing for six to twelve months. Then the week repeats itself.
- Chronic cluster headaches - in this case the cluster periods can persist for several months, even for a year or longer. While periods of remission (periods with no pain) are short; perhaps just a month long.
- Daily occurrences, with symptoms appearing several times each day.
- Just one attack, lasting from 15 minutes to up to three hours.
- Attacks occur each day at approximately the same time.
- Most attacks occur between 9pm and 9am (source: The Mayo Clinic, USA).
If you start getting headaches, it is advisable to see your doctor. Usually, headaches do not have an underlying cause (some illness or condition). However, sometimes they do. It is important for the doctor to rule out any possible underlying causes.
Risk factors for cluster headaches
Many males who experience cluster headaches are smokers.
For example, obese people are more likely to develop diabetes type 2 compared to people of normal weight. Therefore, obesity is a risk factor for diabetes type 2.
Risk factors for cluster headaches include:
- Being male - approximately 8 in every 10 sufferers are male.
- Being an adult - nearly all suffers say their cluster headaches started after they were 20 years old.
- Ethnic ancestry - people of African ancestry are twice as likely to suffer from cluster headaches, compared to Caucasian people.
- Smoking - the majority of male sufferers are smokers.
- Alcohol consumption - a significant proportion of sufferers claim that alcohol is a key trigger during a cluster period (not during remission periods).
- Genetics - if you have a close relative (parent or sibling) who has (had) cluster headaches, your risk of having them yourself is greater.
On the next page, we look at the causes, treatments and prevention of cluster headaches.