When I finally decided to give blood, I didn't know what I was letting myself in for. I'd thought about it for a long time, but I'd never got around to it. Then, while out for a drive, I spotted a sign giving directions to a community centre where a session was taking place. I suppose I'd thought to nip in - much like Tony Hancock in The Blood Donor - offer up a drop of the red stuff and forget all about it. But of course, it isn't that simple in this day and age; when you give blood today, you sign up to a long term commitment. The first pint is for analysis; then, if it's a good vintage, you go into a database and more or less join a society.

Here's how it pans out. About a week after giving blood you are sent a letter, explaining that you will receive notification of local donor sessions. With this letter is a plastic card, which you present when you turn up. It is the size of a credit card, and - below the words 'I Give Blood. I Save Life - is your name, your blood group (A Rhesus Positive, in my case), and your donor number. Now you are ready to give blood in earnest.

I'm happy to sign up to this club, but I'm somewhat amused by the incentive they offer to keep you interested. The donor card is an attractive red number, but you can earn a sort of promotion. This card is for sessions 1 to 4. After this, you will receive a green card, which you will present at sessions 5 to 9. Progression is slower after this. A yellow card will cover sessions 10 to 24 ( I should point out that there is a period of 16 weeks between sessons), and so on until you get a magic purple card (the 7th and final one) which you will receive after a hundred donations; If I've done my math right, I'll be 55 when I get that one!

Among the interesting facts; Blood makes up about 7% of your body's weight: A newborn baby has about one cup of blood in its body; There are around one billion red blood cells in 2 to 3 drops of blood; Earthworm, leeches and insects have green blood; Lobsters and crabs have blue blood because it contains copper instead of iron; There is NO substitute for human blood.

Hmm. I think I'll make an effort to get that purple card;-) www.welshblood.org.uk