23/05/2017 12:04 BST | Updated 23/05/2017 13:05 BST

How And Where To Give Blood: Donation Rules In The UK Explained Following Manchester Attack

'Book an appointment in the next few days or weeks, don’t just turn up.'

In light of the Manchester terror attack, people are asking how they can help in a time of crisis. For many, the answer is simple: give blood.

An NHS Blood and Transplant spokesperson has advised that no more blood is needed to help those injured in the attack and has instead urged people to donate blood regularly throughout the year to ensure there is always enough. 

The service needs 6,000 units of blood to be donated every day across the country, so having a steady stream is vital. 

If you haven’t given blood before, it can be hard to predict what the process will entail, as well as whether you need to meet any requirements beforehand. 

Here’s what you need to know about it:

Who can give blood?

To give blood, you must be fit and healthy. You should also weigh over 7 stone 12lbs (50kgs) and be aged between 17 and 69. 

If you are aged 70 or over, you can give blood if you’ve donated in the past two years.  

Additionally if you are pregnant, you can’t give blood. 

How often can you give blood?

Men can give blood every 12 weeks, while women can give blood every 16 weeks. This is partly down to body size and weight, as well as taking a woman’s menstrual cycle into account.

Can you give blood if you’re gay?

Official guidance is that men who last had sexual contact with other men more than 12 months ago can give blood. This is to minimise the risk of passing on blood-borne diseases, infections and viruses, according to NHS Blood and Transplant. 

“We can’t collect blood from men who have had oral or anal sex with men, with or without protection, in the last 12 months,” its website states.

“This isn’t meant to be discriminatory. It’s not based on anyone’s sexual history or sexuality. It reflects statistical risks for the sexual behaviour that increases the risk of virus transmission.” 

Things to consider before giving blood.

It’s important that you eat regularly before donating to keep blood sugar levels stable. Equally, it’s important to remain well-hydrated in the days leading up to it and get a good 7-9 hours sleep the night before, the NHS advises. 

Experts recommend avoiding any vigorous exercise or heavy lifting on the day of your donation. They also recommend wearing clothing with sleeves that can roll up past your elbow, for easy access to veins.

What happens when you give blood?

On the day of your donation, you will be taken for a private health screening to ensure it’s safe for you to donate. You will then be seated in a waiting area, where you’ll eventually be invited to a donation chair.

When called upon to donate, a blood pressure cuff will be placed on your arm to maintain a small amount of pressure during your donation. Medical staff will examine your arm to find a suitable vein before cleaning the area with an antiseptic sponge.

“Donors are advised to do applied muscle tension exercises during donation,” reads NHS Blood and Transplant’s site. “This is to maintain blood pressure and promote wellbeing during and after donation.”

After the needle has been inserted, you should feel comfortable. Any discomfort should be reported to staff.

Throughout the process, a scale will constantly weigh and measure your donation. This will stop automatically when your donation is complete.

A full donation is 470ml and will usually take between 5 and 10 minutes.

Once you’ve donated, the needle will be removed and a dressing will be applied to the arm. Patients are advised to leave the dressing on for six hours and to avoid using their arm to push on or carry anything heavy. 

How to register.

You can register to donate blood online via the NHS Blood and Transplant website.

Where can you give blood?

You can give blood at donation centres dotted across the UK. To locate your nearest centre, use this postcode search.

Giving blood in an emergency.

NHS Blood and Transplant will often have a contingency plan in emergency situations such as a terror attack.

“Our usual blood stocks allow for something like this happening,” a spokesperson told HuffPost UK. “No more blood is needed in emergencies like this than in car accidents or pile-ups.

“If hundreds of people were affected, however, it would be different.”

In an event like the Manchester attack, the service will simply monitor the blood stocks they have. If they need extra blood, they can request it from other cities across the UK such as Birmingham or Bristol.

The general advice in an emergency is that people shouldn’t turn up and donate immediately after the event takes place, as this can put pressure on services. 

“Blood used for patients injured in an attack will have been donated roughly a week ago,” a spokesperson said. 

They have urged people to plan ahead and donate in the coming weeks to help ‘top up’ depleted stocks.

“If you are registered, think about when you are due to donate,” they explained. “Book an appointment in the next few days or weeks, don’t just turn up.

“We need to top up the stock for the next few weeks, so donating afterwards would be helpful. If people come now, we can’t top it up.”