Cluster Headache: Symptoms, Causes and Treatment

01Definition

What cluster headache is

Mayo Clinic describes cluster headache as a rare and severe type of headache that causes intense pain in or around one eye on one side of the head, typically the most painful type of headache. Several headaches occur over short periods, forming a cluster. The NHS explains that cluster headaches are not caused by another illness, can have a real impact on life, and that treatments can help.

MedlinePlus notes that cluster headache may be confused with other common headaches such as migraine, sinus headache and tension headache. Mayo Clinic adds that recent studies suggest women may be misdiagnosed with migraine or sinusitis. Our guide to sinus headache explains that condition.

02Attack

Typical attack: pain and eye or nose signs

According to the three sources, a typical attack involves:

• sharp, stabbing, burning or piercing pain in, behind or around one eye, which may spread to the face, head and neck
• pain that starts quickly without warning, peaks within 5 to 10 minutes and ends as suddenly as it began
• attacks lasting 15 minutes to 3 hours, often 30 to 45 minutes
• restlessness: people often pace, rock or move around
• on the same side: a red, watering eye, a drooping or swollen eyelid, a smaller pupil and a blocked or runny nose
• sweating of the forehead or face, and sometimes nausea

Mayo Clinic notes that some people first have migraine-like nausea or aura. After an attack, most people are pain-free but exhausted.

03Periods

Cluster periods and remission

During a cluster period, Mayo Clinic explains that headaches usually come every day, often several times a day, frequently at the same time, and most often at night, 1 to 2 hours after going to bed. MedlinePlus notes that attacks commonly strike 2 to 3 hours after falling asleep. Cluster periods often start at the same time of year and last a similar length of time.

In episodic cluster headache, a cluster period of a week to a year is followed by a pain-free remission. In chronic cluster headache, attacks continue for a year or more without a meaningful break. The NHS notes that gaps between clusters can last weeks, months or years, or there may be no gap at all.

04Causes

Possible causes and triggers

The exact cause is unknown. Mayo Clinic and MedlinePlus explain that the regular timing suggests a link with the hypothalamus, the part of the brain that helps run the body clock; MedlinePlus also mentions the release of chemicals such as histamine or serotonin around the trigeminal nerve of the face. Cluster headache is more common in men, usually starts between 20 and 50, and can run in families.

The sources list triggers that may provoke attacks, especially during a cluster period:

• drinking alcohol and smoking, the most common triggers
• strong smells such as perfume, paint, nail varnish or petrol
• exercise or exertion, heat and bright light
• high altitude, weather changes, foods high in nitrites and certain medicines

Mayo Clinic notes that many people with cluster headache smoke, but quitting smoking usually does not stop the headaches.

05Diagnosis

How it is diagnosed

There are no specific tests for cluster headache. The NHS and MedlinePlus explain that diagnosis is based on a description of the pain, its location and frequency, other symptoms and the medical history. If examined during an attack, a drooping eyelid or small pupil (Horner syndrome) may be seen on the painful side; these signs are not present at other times.

Because other conditions can cause similar symptoms, a doctor may request a brain scan, such as MRI, to rule out other causes. Mayo Clinic advises seeing a professional when cluster headaches first start, and if an established headache pattern changes.

06Attack treatment

Treating an attack

The NHS explains that usual painkillers such as paracetamol and ibuprofen do not work, and MedlinePlus notes that pain medicines take too long to act. Treatments for an attack that has started include:

• triptans, usually given as an injection or nasal spray
• breathing high-flow oxygen through a mask
• a device that delivers mild electrical pulses to the back of the neck
• other prescription medicines chosen by a specialist

MedlinePlus warns that some attack medicines can be dangerous if combined, so treatment should be prescribed and supervised by a doctor. Rarely, when other options fail, an implanted nerve stimulator may be offered.

07Prevention

Preventive treatment

Medicines can also help prevent attacks before they start. The NHS lists corticosteroids, verapamil and lithium; MedlinePlus also mentions some blood pressure, seizure and antidepressant medicines and treatments that block a protein called CGRP.

Preventive medicines need medical supervision and regular review. Treatment choices, doses and monitoring are decided by your doctor, and approvals and availability differ between countries.

08Daily life

Living with cluster headache: sleep, alcohol, work

MedlinePlus notes that cluster headaches are not life threatening and do not usually cause permanent changes to the brain, but they can be painful enough to interfere with work and daily life, and they may become less frequent with age. MedlinePlus advises stopping smoking and avoiding alcohol and any foods that trigger attacks.

MedlinePlus suggests a headache diary noting the day and time the pain began, what you ate and drank, how much you slept, what you were doing and how long the attack lasted. Reviewing it with your doctor helps identify triggers and patterns, but a diary should not delay assessment of new or changing headaches.

09Sources

Where the sources differ

The sources describe remission differently: MedlinePlus (October 2025) says pain-free periods last at least 1 month, while Mayo Clinic (August 2025) speaks of remission lasting three months or longer in episodic cluster headache. Classification details vary, so no single threshold is given here. The NHS page (reviewed August 2023) was due for review in August 2026 and has not yet been updated.

The NHS lists treatments in a UK context, while Mayo Clinic and MedlinePlus refer to medicines approved in the US. Treatments for attacks and prevention, including oxygen, are prescribed and supervised by a doctor. MediBilbao Salud does not treat cluster headache; the right step is assessment by your doctor or a neurologist.

10Summary

In summary

Cluster headache causes severe, one-sided pain around the eye lasting 15 minutes to 3 hours, often at night and at the same time each day, with a red, watering eye or blocked nose on the same side. Attacks come in clusters lasting weeks or months. Usual painkillers do not help; triptans, oxygen and preventive medicines prescribed by a doctor do.

To review your plan with your doctor, it helps to keep separate notes on what you use for attacks and what you take to prevent them, how well each works, any side effects, and when to return if the pattern changes or treatment stops working. A sudden thunderclap headache, fever with a stiff neck, weakness, speech problems or a new drooping eyelid need emergency care.