A London man is reaching out to people who suffer from a rare, and debilitating type of headache, called a cluster headache.

The cause of cluster headaches is something of a medical mystery, but the pain is very real.

The agonizing moments were captured by Londoner Tom Termeer and posted on YouTube.

For him, cluster headaches are a painful part of life, "It feels like being shot repeatedly, over and over again."

Neurologist Dr. Paul Cooper is a headache specialist with the London Health Sciences Centre.

He says, "This is sometimes referred to as the 'suicide headache,' because patients say if the headache were carrying on that they would think about committing suicide very seriously because the pain is so intense."

The exact cause of cluster headaches isn't known, but they're more prevalent among men and typically the symptoms first appear between the ages of 20 and 50.

"Not all attacks are the same severity. They range from a one to 10 scale, a 10 I would perish if this house was on fire...you cannot even comprehend or form a thought during a severe attack," Termeer explains.

Cooper says medications are used to treat cluster headaches but, "Cluster often is resistant to treatment. So what one tries to do is give the patient a medication that will turn off the attack when they're having the attack."

Pain management has been elusive for Termeer, but he's channelled his energy into making people aware of cluster headaches through his blog.

"We just need to help others that are in that dark place, to try to get out of it. By motivating them and inspiring them to realize there's more to life than the attacks."

He draws strength from his family, which includes his son Zack, with whom he shares a love of classic cars, and his wife Kristin, who says he's an inspiration.

"He's my hero."