By Jane Elliott
Health reporter, BBC News
Mike Pollock says he has had cluster attacks since he was seven
Every day for the past 20 years Mike Pollock has had at least two headaches, often three.
One day he had 15 separate headaches.
There is no cure and he has been in so much pain that he has considered suicide.
"I have been suffering from cluster headaches, also known as suicide headaches, since I was seven," he said.
"Up until 20 years ago I was what is called episodic - the headaches would come for four to five months every couple of years and then they would go away. Then I went permanent and have had attacks every single day.
"I did seriously contemplate suicide.
"The pain is unbearable - you go round with your hand to the pain and scream."
He recalled how one morning at 4.30, as he stood in his back garden having an attack, he seriously thought about taking his own life.
"I went into the garage because I knew there was some rope there, but my son had used the rope to tie all his toys up.
"At that time it was such a bad headache I would have done it. The irony was that five minutes later the attack finished."
Mike, 63, from Hertfordshire, said the only thing that can alleviate the excruciating pain are injectable drugs.
But, because he can take no more than two a day, he often has to endure untreated attacks.
He was among the first patients to try a technique called occipital nerve stimulation in which a nerve in the brain is connected to a battery pack in the body that can send electrical impulses to quell the pain.
"It did help a bit but I had it taken out after two years because the battery did not work for long and I didn't want to go into hospital every year for a battery change," Mike said.
Cluster headaches come in clusters several times a day for a number of days, weeks or months.
They may not then occur for months or years, but for some people there's no pain-free period.
Headaches can last from 15 minutes to three hours.
They affect men more than women.
He has found other methods help to ease his condition, but nothing is completely effective.
"I have also found oxygen helps, but it is slow to work.
"The injections work every time, but you can only use twice a day. I have boxes and boxes of the injections and have used them in cars, planes, trains."
Mike, a company director, said his condition affected every aspect of his life.
"I have not had a drink for 20 years as you have to avoid alcohol, which makes life boring, but you will never find a cluster headache sufferer who is either in cycle or chronic who drinks," he said.
"I always have an attack about an hour-and-a-half after going to sleep, one between 8.30am and 9am every morning and maybe one in the afternoon.
"It is depressing because driving to work every day I know I am going to get a headache.
"Every woman I have ever spoken to says the pain is worse than childbirth."
In May a conference run by Ouch (the Organisation for the Understanding of Cluster Headaches) and the Migraine Trust is set to highlight the problems of rarer headaches and tell sufferers about new treatments and research.
Peter Goadsby, professor of neurology at the University of California, San Francisco, and the Institute of Neurology, London, will speak at the conference.
"Cluster headache is often said to be the most severe pain that humans have," he said.
"I have seen just over 1,000 patients and sadly that statement seems correct.
"Patients simply do not report pains that are worse. So think of the worse thing that has ever happened pain-wise, childbirth included, and cluster headache is worse still."
Professor Goadsby said the conference was vital to highlight an under-recognised condition.
"To put it in perspective, it is about as common as multiple sclerosis," he said.
Wendy Thomas, chief executive of the Migraine Trust, said: "More than 120,000 people in the UK suffer from cluster headache and there are many others with rare types of headache.
"They often feel very isolated as they try to cope with the dramatic impact the condition has on their quality of life.
"It is a great breakthrough for us to be staging the world's first conference on rare headaches along with Ouch - another member of Headache UK - at which health professionals and sufferers will hear new research about treatment options.
"The conference is of vital importance as it will stimulate global research to get more insight into these devastating conditions."