Donating blood regularly is safe and an important public service — here's how often you can donate

• You should donate blood a max of six times per year.
• You can donate platelets 24 times a year, and plasma 12 times a year.

If you give blood regularly, don't fret. Contrary to common misconceptions, blood donations are not associated with premature death or cancer. By donating blood, you'll be saving multiple lives.

Every two seconds, someone in the United States needs some type of blood transfusion, and a single donation can save as many as three lives. Moreover, it's safe to donate blood several times a year, and institutions use sterile equipment for each donor to eliminate the risk of contracting infections.

That said, not everyone can become a blood donor. Certain health conditions may affect your eligibility to donate blood, such as dementia or human immunodeficiency virus (HIV) infection.

Here's what you need to know about how to become a blood donor safely.

How often can you donate blood?

When donating blood, there are several different ways to go about it. You can donate whole blood — everything in the vial. Or, you can donate blood components like plasma, red blood cells, and platelets, where a machine separates your blood into the various components and then returns the leftovers to your body.

The main difference between each donation is how often you can safely do it.

"You can donate whole blood every 56 days or up to 6 times a year," says Bruce Sachais, MD, PhD, chief medical officer of the New York Blood Center. That's because, "it takes the body four to eight weeks to replace red blood cells," says Sachais." On the other hand, you can donate platelets and plasma more frequently.

Medical term: Platelets are blood cells that form clots to stop the bleeding, and plasma is the liquid part of blood that carries the proteins that are vital for blood clotting.Red blood cells are bring oxygen from your lungs to the rest of your body and carry away CO2.

"Platelets may be donated up to 24 times a year and plasma up to 12 times a year," says Sachais. You can donate more frequently because the body replaces plasma and platelets faster than red blood cells.

"Donating blood is a safe activity," says Tho Pham, MD, chief medical officer of the Stanford Blood Center. However, if you donate too often, you may develop anemia, a condition where your blood doesn't have enough red blood cells, he says.

"That's one of the main reasons why we check the donor's hemoglobin level before every donation [—] to ensure that it is high enough," says Pham. "Based [on] extensive research over a long period, the FDA has established federal guidelines around how often and how much individuals can donate blood so as not to compromise their health."

Who isn't eligible to donate blood?

Blood donors should usually be at least 18 years old, but 16 to 17-year-olds may donate with written consent from their parent or legal guardian. There is generally no upper age limit, but some institutions require a physician's letter for donors above 75 years old.

"While about 38% of the US population can donate blood, others may be ineligible for a wide variety of reasons designed to protect patients who may be receiving the donated blood products or even to protect the donors themselves," says Pham.

Some factors temporarily prohibit you from donating blood, such as:

• Pregnancy: Pregnant individuals can't donate blood because they need additional iron during their pregnancy and because pregnant women tend to develop mild anemia during their pregnancy. They need to wait six months after giving birth before they can donate blood safely.
• Tattoos: If you recently had a tattoo in a state-regulated facility that used sterile needles and new ink, you can donate blood with no problem. However, if your state does not regulate tattoo facilities, you'll have to wait three months before donating blood to minimize the risk of spreading transfusion-transmissible infections such as syphilis or HIV.
• Medications: Taking certain medications makes you temporarily ineligible to be a blood donor, and the waiting period after your last dose depends on the medication that you took. For example, you can only donate blood seven days after you stopped taking blood thinners such as Coumadin or Warfilone, but you have to wait three years after your last dose of Soriatane, the oral retinoid treatment for psoriasis.
• Recent travel: Visiting areas that are associated with a greater risk for mosquito-borne infections, such as malaria, dengue, and Zika virus, may keep you from donating blood either temporarily or permanently, depending on location.

However, certain conditions permanently rule you out from becoming a blood donor, such as:

• Anemia
• Dementia
• HIV, even if the condition is controlled
• Hepatitis B or C
• Hemophilia, a disorder where the blood doesn't clot normally
• Leukemia, even with a current or previous history
• Stroke, even if you've recovered
• Syphilis

There are plenty of eligibility criteria to become a blood donor. If you're unsure whether or not you qualify, you can get in touch with a blood center near you to walk you through your eligibility.

How to donate blood safely

Prior to your blood donation, there are several things you have to keep in mind, such as:

"Since donating whole blood temporarily decreases the amount of red blood cells, and therefore hemoglobin, in your system, it's advisable to take an iron supplement, especially after your donation, to give your body a little extra boost as it starts creating more red blood cells," says Pham.

Eating foods that are rich in vitamin C, such as citrus fruits, bell peppers, strawberries, helps you absorb iron better.

Insider's takeaway

You can donate one pint of blood every eight weeks, and it will take your body four to eight weeks to replace the number of red blood cells that you lost. You might not be allowed to donate blood depending on your medications, recent travel history, or certain health conditions like HIV, hepatitis B or C, or dementia.

Avoid drinking alcohol and eating fatty foods before your blood donation. Instead, get adequate sleep, drink plenty of water, and eat foods that are rich in iron and vitamin C to stay healthy and help your body create more blood cells.

"Long-term donation is safe. Many blood donors donate regularly over decades without health issues. Good nutrition, including eating iron-rich foods, help ensure blood levels return after each donation," says Sachais.