If you knew you had a potentially fatal medical condition but you were prevented from getting the treatment that could save your life, how would you feel?

With this thought in mind, today I telephoned Tayseer Mahmoud Rajab, a 52 year old man living in Gaza. His wife answered the phone. She told me that he wanted to talk to me but he was embarrassed to do so. I was surprised, but it soon became clear to me why. Tayseer has a brain tumor. One of the symptoms of this illness can be involuntary changes in behavior.

I know that in a few days or weeks the family may no longer recognize the Tayseer they know. He will be totally different: antisocial, depressed and indifferent. His family will be devastated, I've seen it many times. I've also seen how rapidly people can go back to their normal state once the tumor is removed - but will his tumor ever be removed? The prospects for that are not good, since he cannot leave Gaza.

Tayseer's wife told me that he feared that he would be aggressive and irritated with me on the phone, as he sometimes is at home now. So throughout my conversation Tayseer stayed beside his wife, answering the questions that I asked her.

Tayseer used to work as an electrician in Israel. Last June the blockade of Gaza started and he wasn't allowed to enter Israel anymore. Now it is his two sons who work to feed the family. One of them drives a microbus (which is not profitable, given the increase in fuel prices caused by the blockade). The other sells bagels in the street. The little income that they make is not really enough to feed the entire family.

A month after losing his job, Tayseer started suffering from headaches and blurred vision. The doctors in Gaza told him that he had a brain tumor but they were unable to diagnose his case any further. His case needed advanced diagnostic equipment and very skilled surgeons to deal with the tumor. These things are not available in Gaza where even the ordinary medical supplies are in short supply. He was referred to hospitals in Israel so that doctors there could find out more about his illness and decide the ideal line of treatment, treatment that could potentially prolong his life.

It took a couple of months to make the general diagnosis and to schedule the appointment with the Israeli Hospital, which was finally made for him for 2 November. But it is now February and Tayseer has not yet been allowed to exit Gaza to visit the hospital. It goes without saying that tumors, especially brain tumors, have to be treated promptly otherwise the damage is irreversible and eventually fatal.

On November the 2nd Tayseer made his journey to the Erez Crossing to enter into Israel, but was prevented from doing so. Apparently, the Israeli soldiers at the border were not convinced that he was ill, although he had all his medical reports and referral documents with him. With the little strength that he had, he appealed through human rights organisations so that he could get a court order that would allow him to cross into Israel. It did no good.

His appointment was rescheduled and on the 2 December he showed up again at the crossing once more but was denied entry. Why? The reason he was given was the same as the last.

The last few months have been cold and without a job it has been difficult to find the money to keep warm and to eat. Like many other families in Gaza now, Tayseer's has been using a wood fire to warm his house. On some days he cannot even afford to buy bread. However, bread is the least of his worries at the moment. On top of his illness, Tayseer's son has an advanced case of skin disease called psoriasis; he needs to rub his whole body with an ointment every night.

The price of a single tube is 40 shekels (US$11 / £5.60 / €6.75), and he needs one every other day. As a doctor I know that this is a simple case that does not require referral to an advanced hospital. All it requires is an ointment that is sold in drug stores everywhere in the world. But in Gaza, such an ointment, even if available, is unaffordable to people without jobs.

Tayseer is not the only person in Gaza that has been denied treatment. In Shifa hospital in Gaza city, 135 cancer patients are currently unable to receive treatment due to the lack of basic medications. How many deaths will we see before Israel relents and allows the sick and the elderly access to care that they need?

Posted by: Abbas, a doctor working in partnership with Oxfam GB