Cluster headaches are excruciating unilateralheadaches of extreme intensity. The duration of the common attack ranges from as short as 15 minutes to three hours or more.

The onset of an attack is-- rapid, and most often without the preliminary signs( that are characteristic of a migraine).

However, some sufferers report preliminary sensations of pain in the general area of attack, often referred to as "shadows", that may warn them an attack is lurking or imminent.

Though the headaches are almost exclusively unilateral, there are some documented as cases of "side-shifting" between cluster periods, or, even rarer, simultaneously (within the same cluster period) bilateral headache.

A wide variety of prophylactic medicines are in use, and patient response to these is highly variable. Current European guidelines suggest the use of the calcium channel blockerverapamil at a dose of at least 240 mg daily. Steroids, such as prednisolone/prednisone, are also effective, with a high dose given for the first five days or longer (in some cases up to 6 months) before tapering down. Methysergide, lithium and the anticonvulsanttopiramate are recommended as alternative treatments. In Australia, Neurologist John Watson has also reported success with Epilim and Tegretol in some chronic, treatment-refractory cases.

Intravenous magnesiumsulfate relieves cluster headaches in about 40% of patients with low serum ionized magnesium levels. ]Melatonin has also been demonstrated to bring significant improvement in approximately half of episodic patients

Over-the-counter pain medications (such as aspirin, paracetamol, and ibuprofen) typically have no effect on the pain from a cluster headache.

Medications to treat cluster headaches are classified as either abortives or prophylactics (preventatives).

In addition, short-term transitional medications (such as steroids) may be used while prophylactic treatment is instituted and adjusted. With abortive treatments often only decreasing the duration of the headache and preventing it from reaching its peak rather than eliminating it entirely, preventive treatment is always indicated for cluster headaches, to be started at the first sign of a new cluster cycle.

Interventional pain procedure:

Sphenopalatine ganglion block. This is usually done under fluoroscopy( mobile X- ray mechine) guided in procedure room.

During the onset of a cluster headache, many people respond to inhalation of 100% oxygen (12-15 litres per minute in a non-re-breathing mask. There is also a study (commenced 2011) using an "on-demand" valve that can deliver up to 160 litres per minute. When oxygen is used at the onset this can abort the attack in as little as 1 minute or as long as 10 minutes. Once an attack is at its peak, oxygen therapy appears to have little effect so many people keep an oxygen tank close at hand to use at the very first sign of an attack. An alternative first-line treatment is subcutaneous or intranasal administration of sumatriptan.[20]Hyperbaric oxygen therapy has been used successfully in treating cluster headaches though it was not shown to be more successful than surface oxygen.

See your doctor if you've just started to experience cluster headaches to rule out other disorders and to find the most effective treatment. Headache pain, even when severe, usually isn't the result of an underlying disease, but headaches may occasionally indicate a serious underlying medical condition, such as a brain tumor or rupture of a weakened blood vessel (aneurysm). Additionally, if you have a history of headaches, see your doctor if the pattern changes or your headaches suddenly feel different.

if you have any of these signs and symptoms:

• Abrupt, severe headache, often like a thunderclap
• Headache with a fever, nausea or vomiting, stiff neck, mental confusion, seizures, numbness, or speaking difficulties, which may indicate a number of problems, including stroke, meningitis, encephalitis or brain tumor
• Headache after a head injury, even if it's a minor fall or bump, especially if it gets worse
• A sudden, severe headache unlike any other headache you've experienced
• Headache that worsens over days and changes in pattern