Everything you need to know about blood donation

Every day, Americans use about 29,000 units of red blood cells, according to the American Red Cross. It’s a life-saving treatment that’s always in high demand. Partially because blood donations don’t last forever. 

“Unlike other lifesaving treatments, blood products are perishable and cannot be stockpiled or manufactured,” says Yvette Miller, MD, executive medical officer of the American Red Cross. Red blood cells have a shelf life of 42 days, while platelets must be used within five days. 

In 2022, the American Red Cross experienced its first-ever blood crisis, with the worst blood shortage in over a decade. And while the need has stabilized, blood banks always face a chance of a shortage.

That’s because only about 3% of eligible people donate blood every year. If you’re looking for an easy way to help your community and are donating for the first time, read on to learn the basics.

Blood donation requirements

The first step in giving blood is to find out if you’re eligible to donate blood and where to donate. 

Who can give blood?

The main eligibility requirements are age and weight: You have to be at least 16 years old, weigh over 110 pounds, and be in good health.

To help maintain the safety of the blood supply, there are some blood donation disqualifications such as certain health conditions, travel destinations, and other risk factors that make you ineligible to donate including anemia, pregnancy, cancer, HIV infection, hepatitis, a history of Ebola virus, active tuberculosis, or Creutzfeldt-Jakob Disease (CJD).

If you have new tattoos (unless done in a state-regulated facility with sterile needles and non-reusable ink) or piercings (unless they were done with disposable, single-use equipment), you’ll be required to wait three months.

Previously, there were blood donation eligibility restrictions that prevented gay and bisexual men from donating. But the U.S. Food and Drug Administration (FDA) updated its guidelines on May 11, 2023. The current policy implements an individual risk assessment, which states that all donors, regardless of sexual orientation or gender, can’t donate blood if any of the following statements regarding sexual contact are true:

• The donor reports having a new sexual partner in the last three months.
• The donor has had more than one sexual partner in the last three months.
• The donor has had anal sex in the past three months.

RELATED: Who can donate blood—and who can’t

Where to donate blood

To find a blood drive or donation center near you, search the American Red Cross website, the America’s Blood Centers website, or AABB.org. You may be asked to fill out a short online questionnaire with basic information, such as your name, birth date, and contact information. Many local donation centers will let you select a time slot online. Then, you just need to arrive at the center on the date and time of your appointment.

If you prefer, you can also call 1-800-RED-CROSS. If you’re a frequent donor, you can often create a username and password with your local center to make it easier to sign up in the future.

The blood donation process

Blood donation is safe, fast, and most people won’t experience any side effects. However, there are certain steps you can take to make sure your first blood donation is a positive experience and that you feel your best after giving.

What to do before donating blood

“Preparing for a blood donation should begin at least one day before donors enter a blood drive or blood donation center,” Dr. Miller says. “It is recommended that individuals eat a nutritious meal the night before, get a good night’s rest and drink extra liquids.” 

All of those steps will help make sure you’re in optimal physical condition for the donation. Dehydration increases the chances of feeling faint after donating and makes it harder for the phlebotomist to find a vein. As for the day of, Dr. Miller recommends drinking an extra 16 ounces of water and eating a healthy meal.

At your blood donation

At your appointment, you’ll verify your personal information. Next, you’ll provide details about your medical history, including current medications. 

“Potential donors will be asked questions during a private and confidential interview about their personal health history and places traveled,” Dr. Miller says. This is used as a screening tool to make sure your blood is safe to donate, so be sure to answer the questions honestly. At this time, you’ll also have your temperature checked as well as your hemoglobin levels, blood pressure, and pulse.

“As long as you are not anemic and are negative for other conditions, you can give blood,” says Kim Langdon, MD, expert contributor to Parenting Pod.

Then, it’s time for the actual blood collection. You’ll be positioned in a comfortable location either sitting or laying down. “Staff will clean the donor’s arm, and following a quick pinch, the bag will start filling,” Dr. Milles explains. “When approximately a pint of blood has been collected, the donation is complete, and a staff member will place a bandage on the arm.” 

Many people wonder how long does it take to donate blood. Whole blood donation takes around 10 minutes. If you’re donating plasma or platelets, it could take longer. Those types of donation use a process called apheresis, which simply means your blood is filtered through a machine attached to both arms while you give. The machine takes the part of the blood the center needs and returns the rest to your body. This process can take up to two hours for plasma donation and platelet donation.

After donating blood

When your donation is finished, you’ll be given a drink and a snack, along with instructions on how to take care of yourself after donating. It’s all about replacing the fluids you lost by giving blood, according to Joyce Mikal-Flynn, Ed.D., FNP, founder and originator of MetaHab.

Some people experience side effects from donating blood, like feeling faint, light-headed, dizzy, nauseous, or sweaty. Usually those symptoms only last a few minutes, and improve after food and hydration.

You may also have a bruise where the sterile needle was inserted. If you experience continued nausea or lightheadedness, pain or numbness in your arm, a raised bump, or continuous bleeding, you should contact your healthcare provider or donor center. However, blood donations are not harmful to a healthy individual.

Typically, post-donation instructions include eating a well-balanced meal, staying hydrated, and avoiding smoking or drinking alcohol for at least 24 hours. Wait eight weeks before donating blood again.

Benefits of blood donation

After your donation, your donated blood is sent to a processing center. Most often, it is separated into its three blood components: plasma, platelets, and red cells. Each part can be used to treat different needs. It’s packaged into units of blood, which are standard amounts used to give transfusions. Blood donations are distributed to hospital blood banks. 

“The most obvious reason to donate is to help people,” Mikal-Flynn says. “Even during this time, traumas occur. Blood is needed to help with patient care.” Patients might need transfusions if they bleed a lot during an emergency, like a car accident or surgery. They can also be part of treatment for certain health conditions, like cancer or sickle cell anemia.

“African American blood donors can help patients battling sickle cell disease,” Dr. Miller says. “Sickle cell patients are predominantly of African descent and require frequent blood transfusions from individuals that are of similar race and ethnicity to prevent complications during transfusion therapies.” 

When your blood is prepared to help others, it is tested for blood type and certain conditions. That’s one perk of donation, besides helping people: It’s a free health screening. You’ll be notified of any positive tests and can find out about underlying conditions, like low iron. Blood donation can help reduce the risk of strokes or blood clots in patients with sleep apnea and hemochromatosis and those on testosterone treatment. 

You will also learn your blood type: A, B, AB, or O. There are specific ways that blood is matched for a safe blood transfusion, and blood type is part of that. Type O- is the universal blood type, meaning, it can be given to patients with any blood type. Type AB+ plasma is the universal plasma donor. If you have one of these blood types, your donation is even more valuable, since it’s the most requested, and often in scarce supply.

A single blood donation can save up to three lives, according to the American Red Cross. Blood can’t be manufactured; it has to be given by healthy people. Someone in the U.S. needs blood every 2 seconds. That adds up to 5,000 units of platelets and 6,500 units of plasma. Your appointment could help be part of the solution for someone in need.

Blood donation FAQs

What to eat before donating blood? 

Before donating, the American Red Cross recommends consuming iron-rich foods such as fish, poultry, red meat, legumes, spinach, iron-fortified cereals, or raisins. On the day of your appointment, be sure to drink plenty of water (at least 16 ounces), and eat a healthy meal that’s low in fat. That means avoiding fried foods like french fries and saturated animal fats like bacon.

How long does donating blood take?

According to the Red Cross, blood donation itself takes about eight to 10 minutes, but the entire process will take about an hour and 15 minutes. That said, the exact timing can vary based on your health history as well as staffing and attendance on the day of your donation.

Can you donate blood if you are anemic? 

No. Before your donation, your finger will be pricked to test your blood’s hemoglobin level. Hemoglobin is a protein that gives your blood its red color and contains iron. If your level is lower than 12.5g/dL for women or 13.0g/dL for men, you cannot donate blood until your iron levels increase. To raise your hemoglobin levels, consuming a diet rich in iron and Vitamin C or taking an iron supplement can help, but ask your healthcare provider about the best approach for you.

How long do you have to wait to donate blood again?

It’s required to wait eight weeks between whole blood donations. You can donate up to six times per year. That’s because it takes four to six weeks for your red blood cells to replenish.