Blood donations tend to dip in summer

Carterson says that generally in the summer, donations dip. This is partly because college students — a crucial group for blood donations, Carterson notes — are off of school, and partly because “people are just going out more, having fun and not necessarily thinking about donating,” he tells NBC News BETTER.

It’s time for everyone to step up — especially millennials, which Carterson says “make up the most [ethically] diverse population in the U.S.” This is important because patients with sickle cell diseases and other illnesses that require blood transfusions are more likely to be a match with people of the same ethnic background.

A new survey from Abbott found that just 12 percent of millennials are regularly donating blood.

Though the American Red Cross and other organizations are always communicating the need for blood in the U.S, the urgency seems to simply slip from our minds.

“The need for blood is constant,” says Dr. Sneha Topgi, a NYC-based ER physician with ParaDocs. “I’m ordering blood on a daily basis — whether it’s for trauma patients, people with a gastrointestinal bleed, sickle cell patients or people with cancer who can’t use their own blood.”

So, consider this your reminder to donate blood if you haven’t in a while (you can technically donate every 56 days if eligible, while you need 112 days between platelet donations). We’ve supplied answers to a list of questions you may have about the blood donation process, including how to prep and recover — as well as what to do if you’re a fearful first-timer.

Type O-negative blood is the most in demand as anyone can take it

Though all types of blood are needed, the blood type most sought after is O-negative, as this can be safely administered to anybody whether they’re AB, A+, O+ and so on.

“If there’s a massive explosion or other disaster and there’s a huge need for all types of blood for trauma surgery, physicians grab O-negative,” says Carterson. “There’s a constant supply issue there.”

“If you’re in overall good health and feeling well, you’re probably a candidate for blood donation,” says Topgi.

You need to be at least 17 years old (or 16 with a parent/guardian) and weigh 110 pounds, a rule that was established with the safety of the donor in mind, Carterson says, but one that could change “as the technology around measuring blood volumes improves,” he adds.

You don’t need to know your blood type to donate

If you don’t know your blood type, you can ask your physician to check it at your next physical, but it’s not necessary to know. The staff processing the blood upon donation will be able to tell you and they’ll also issue you a blood donor card that you can keep on you, says Carterson.

Don’t donate blood if you’re hungover, tired or feeling less than your best

There are a great deal of restrictions around blood donations beyond the weight requirement. You can read them all here — but even without a prohibited medical condition, don’t donate blood if you’re not feeling 100 percent.

“Do not come in if you’ve been out partying all night because your body will not handle the stress and shock well,” says Carterson.

Topgi adds to avoid donating blood if you’re feeling a cold coming on or any other illnesses. Essentially you want to be in tiptop shape to avoid any adverse side effects from blood donation, the primary one feeling weak or even fainting, Carterson says.

Lower your risk for feeling faint by eating and drinking before and after (pick iron-rich foods)

You’ll dramatically lower your risk of experiencing these adverse effects if you get a great night’s sleep ahead of donating and eat hearty meals before and after your donation. And by all means, eat the cookies and drink the juice they give you. Your body will thank you for the boost of sugar, carbs and salt — which get depleted upon donation.

“Basically eating the sugary, fatty cookies helps your body realize that everything is okay after the shock of the blood loss and that there’s nothing to stress over” says Carterson. “When we take a unit of blood, we're taking everything with it and your plasma is what distributes nutrients to your blood, so eat up,” Carterson says.

At home (before and after donating), you should focus on eating iron-rich foods and double down on your intake of water. Drinking Pedialyte after is also a good idea, Carterson notes, as this can help restore electrolytes.

Vegetarians and vegans are welcome

If you’re vegetarian or vegan, you can absolutely donate. Just be extra mindful about eating iron-rich veggies and vitamin C.

“Concentrate on foods that are high in iron like spinach, legumes, soybeans and mushrooms,” says Dr. Nate Favini, MD, MS, medical lead at Forward. “Foods that are high in vitamin C can help you absorb more iron. Examples include citrus fruits, Swiss chard and broccoli. You can also consider taking a supplement that has iron it around the time of donation.”

It’s okay to be scared — staff will guide you through the process

If you’re a first-time donor who’s freaked out by needles or the sight of blood, you should divulge this when you check in to donate.

“It’s totally normal to be fearful, so tell them that this is your first time doing it,” says Carterson. “An expert will be there to guide you through it and give you affirmation.”

Expect a mini-physical and clear an hour for standard blood donation

All blood donors are given a mini-physical and asked to fill out a health questionnaire. From start to finish, Topgi says you should expect the process to take one hour “from in and out the door.”

You should be fine to return to work after, but go easy. Definitely don’t hit the gym or go out to the club, and remember, stay super hydrated and well-fed.

Ask about platelet donation. It takes a bit longer but it’s critical for patients.

Platelet donations are a bit more complicated than standard blood donation.

“Platelets’ main function is to help control bleeding by inducing clot formation,” says Dr. Tho D. Pham, MD, chief medical officer at Stanford Blood Center. “During the platelet donation procedure, a machine is used to separate the platelets in your blood from the other red blood cells and white blood cells through a process called apheresis. This is one reason why platelet donations take longer than other donations; allow yourself two hours for the donation process. Although platelet donations are more involved than the others, it is also very important that we constantly get platelets; a unit of platelets only lasts for five days. What’s more, a platelet in your body typically lasts less than a week. So, patients in need of platelets may need a unit of platelets every few days. These patients include those who have been treated for leukemia with chemotherapy and cannot make their own platelets for weeks or months.”

Medical technicians will recommend the number of units of platelets you can donate based on your weight, hemoglobin level and platelet count that day, adds Pham. “You can donate platelets every seven days; however, there is a limit to only 24 platelet donations each year.”

Your blood might be used locally or across the country if needed

Your donation will most likely be transported to the local hospital to “benefit your community”, Carterson says, but notes that it’s not uncommon for blood to be shipped “anywhere in the U.S if there’s a need for it. Blood can stay good refrigerated for up to 42 days — much longer than platelets.”

In any event, your blood will be used, and it’s probably one of the best charitable acts you can make a habit of doing.

“One unit of blood can save three lives,” Carterson says. “It’s truly amazing, we just need to keep getting this message across to do it.”

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