If you are experiencing a cluster headache, one of the most effective methods of near-immediate relief is to inhale 100% oxygen through a mask for a brief period of time. For this method to work properly, you'll need to inhale pure oxygen at a rate of 7 liters (1.8USgal) per minute through a small oxygen mask attached to an oxygen tank that your doctor prescribes for you. Simply breathe normally through the mask for 5-10 minutes. This is a very safe method of treatment with very few side effects for those who use it. The most challenging aspect of using this method is getting access to the oxygen in the first place. You'll need to discuss this treatment option with your doctor so that they can prescribe you a small, portable oxygen tank and an appropriate mask. Triptans are a kind of injectable medication that constricts blood vessels in the brain and are often used to help reduce migraine symptoms. You'll need to contact your doctor for a triptan injection, usually administered in the doctor's office. These kinds of drugs are also available in tablet and nasal spray form, but are often less effective for treating cluster headaches. Don't use sumatriptan (one variety of triptan medication) if you have high blood pressure or heart disease. Some local anesthetics (like lidocaine) have proven effective as treatments against cluster headaches. This medication must be given through the nose by a doctor or other trained professional. Speak to your doctor about this option if you are struggling with chronic cluster headaches.

Summary:
Inhale oxygen. Get a triptan injection. Try a local anesthetic taken intranasally.