Selfless service
At the heart of the Sikh faith there is an emphasis on selfless service, known as Sewa.
"Sewa comes in many forms," says Deepak, a platelet donor who can now count himself among the small number to have reached 100 donation credits. "Whether it's making a donation, feeding someone, or using a skill, you have to help others."
Having started out as a blood donor in Twickenham 13 years ago, Deepak made the switch to platelets after moving to Surrey and now makes the trip to Tooting Donor Centre every month.
But alongside faith, Deepak has another, highly personal reason to donate: his father has myelofibrosis, a type of leukaemia, and receives blood transfusions every three weeks.
Myelofibrosis affects bone marrow, the spongy tissue which produces blood stem cells. These are the so-called 'building blocks' of the body and mature into other, vital cells, including red blood cells.
Blood transfusions help patients like Deepak's father to feel better by increasing the number of red blood cells in their bodies.
Platelet donations are also vital – nearly 70% of donated platelets are used to help people with cancer. Platelets last just 7 days after they've been donated so donations like Deepak's are needed all year round.
"If my father is taking a unit out every month and I put a unit in every month, it sort of balances out," says Deepak. "I feel like I'm helping him in my own way.
"By making the journey into London, I can donate platelets more frequently than whole blood, which allows me to contribute more regularly. Tooting is an hour's drive for me, but appointments are flexible, so I book when I know I'll be in the area on business."
There's a huge need for blood donations, especially within the Black and South Asian populations
Deepak is one of a growing number of donors with South Asian heritage.
More donors like him are needed to help patients who require frequent blood transfusions. Patients who are given multiple transfusions need blood that is closely matched to their own.
"There's a huge need for blood donations, especially within the Black and South Asian populations," says Deepak. "Blood from one's own community often provides a better match, but unfortunately, there's a mismatch between those who need blood and those who give it.
"Donating is free, has no negative impact on your body, and helps directly serve your community while easing the burden on the NHS. We all need to contribute in our own way."
There is currently a particular need for platelet donors with A positive, A negative and AB negative blood types.