Giving blood is a way of life for Mark Allwright.

He has recently donated his 200th pint of blood and has encouraged his wife and children to become donors as well.

Mr Allwright, from Worthing, is carrying on the traditions passed down to him from his parents and members of the family are determined to keep giving blood as often as they can.

Mr Allwright was recently presented with a decanter and thanked by members of the National Blood Service (NBS) for his efforts.

The NBS says it is people like Mr Allwright who help to keep the service going but more donors are always needed as the more people who come forward, the more lives can be saved.

Donors are generally more in demand around bank holidays but supplies also need to be regularly topped-up at other times.

Hospitals are usually a lot busier during school half-terms and the Easter and summer holidays when thousands more people flock to Brighton and Hove and the rest of Sussex.

While blood is needed to help people during major surgery following an accident, those with long-term conditions such as severe anaemia rely on regular tranfusions.

There are four main blood types: O, A, B and AB, with O Positive being the most common making it the one most in demand.

The rarer O Negative is carried by about seven per cent of the population and is even more in demand since it can be given to any patient, regardless of their blood type.

About 23 per cent of donated blood is used for general surgery and 13 per cent for heart and chest surgery.

It is also used for intensive care, gynaecology, blood diseases and orthopaedics.

Anyone undergoing an operation may lose blood but, if it is only a small amount, the fluid can be replaced with a salt or glucose solution.

New red blood cells will then be made by the body over the next few weeks.

However, if a large amount of blood is lost, it will have to be replaced as quickly as possible to prevent the patient becoming dangerously weak.

Platelets are a component of blood and are often needed by cancer patients who have gone through chemotherapy.

They only have a five-day lifespan so turnover needs to be constant and frequent to keep stocks at a high level.

Winter can be a challenging time for blood collection as many people suffer from colds and flu.

The shorter days also mean people who might ordinarily visit a blood donor session on their way home from work are more keen to get home straight away.

Attendance at donor sessions can sometimes fall by as much as ten per cent but demand from hospitals is still high.

A spokesman for the NHS said: "It is vital stocks are maintained at all times. It can be difficult over holiday periods because other people are winding down and relaxing while we have to redouble our efforts. Taking up just a little of your time could help to save someone's life."

The Royal Sussex County Hospital in Brighton uses nearly 13,000 red cell units and 600 platelets each year.

Eastbourne District General averages just over 10,000 red cell units and 900 platelets and at Worthing Hospital the figure is approximately 9,000 and 700 respectively.

Hospitals also have a new method of helping to save precious blood stocks.

Jehovah's Witnesses do not accept transfusions because of their religious beliefs but are promoting the use of special cell-saver machines instead.

These sophisticated machines take out, recycle or "wash" the patient's own blood during surgery and put it back in again which avoids the need for a transfusion.

Witness groups across Sussex have been actively fund-raising for several years to buy and install machines at the county's hospitals in Brighton, Haywards Heath, Eastbourne, Worthing, Chichester and Crawley.

The machines are not only used by patients who are Witnesses but also others where the technique suits their operation.

This means more essential blood supplies are available.

If you are aged between 17 and 60, you can probably give blood. Details about your nearest session and more information is available on the NBS helpline on 0845 7711 711 or at www.blood.co.uk