A Mitcham man who receives regular blood transfusions because of a genetic defect is calling for new donors to come forward.

Theo Bandara, who lives in Melrose Avenue, has thalassemia major and relies on donations to receive three units of blood every 21 days.

People with the condition produce either no or too little haemoglobin, which is used by red blood cells to carry oxygen around the body.

The 35-year-old, who is a clinical coder for the NHS, said: “Donating blood is a complete act of selflessness. To take time out of your day to do something which you are not getting paid for, for a complete stranger, that won’t benefit you is such a noble thing to do.

“What an incredible gesture - my life depends on that gesture and I am forever grateful."

NHS Blood and Transplant is urging people to register this week, which is National Blood Week.

Last year, 900,00 people gave up their time to help patients. But 200,000 new donors are needed each year to ensure future patients have access to blood. The number of active donors in Merton is currently 2,498.

Young blood-givers are particularly important, as they will become the next generation of donors. Half of all donors in England are over 45.

More black donors are also needed. Sickle cell disease, which requires regular blood transfusion, is the fastest growing genetic condition in England and is most common in black people. Around 10,00 black donors gave blood last year, but the NHS say 40,000 more are needed.

Giving blood usually takes no longer than an hour and each donation can save or improve up to three lives.

To sign up as a new donor or book an appointment, visit: www.blood.co.uk or call 0300 123 23 23.