Life Blood

Your blood connects your whole body and tells the story of your health. But how much do you actually know about it? Learn more about the life-giving—and saving—liquid that flows through your veins

According to The Blood Connection, just one pint of donated blood (the average amount taken during a donation) has the power to save up to three lives. Not only can your blood save others’ lives through donation, it also gives your healthcare providers—and you—a detailed look at your whole-body health, potentially elongating your own lifespan. 

“There’s a reason a blood test is often part of your routine well visit,” says Roper St. Francis Healthcare affiliated pathologist Dr. J. Rick McEvoy. “Blood gives us a snapshot of a patient’s health—it provides a diary of what has and is occurring within the body.” Information gathered from blood tests can signal illnesses or imbalances throughout the body, from vitamin deficiencies and hormone issues to cancer, diabetes and other diseases of the blood itself. Having that information can lead to diagnoses and proactive treatment plans, explains Roper St. Francis Healthcare affiliated primary care doctor Matthew Ferguson. 

In addition to being a gold-star preventative and diagnostic tool, routine blood testing also helps people with diagnosed diseases like diabetes, hypertension and clotting disorders monitor their condition and optimize their health (just ask Lowcountry residents Brian Olson and Traci Ray, who share their stories in the following pages).   

All told, blood is a miraculous tissue. And a blood draw—whether it’s to get a closer look at your own health or to save someone else’s life through donation—is more than worth the temporary discomfort. Here, we’re ripping the Band-Aid off to discover what we can learn from our blood, the most common disorders that affect it and how we can boost the health of our circulatory system each and every day. 

Blood 101 

Take a moment to look at the veins in your arm. Thanks to your heart’s pumping power, the blood passing through them right now will soon find its way to your brain, lungs and digestive tract. Arguably, blood’s most important job is to transport oxygen from the lungs to the rest of the body. It also transports nutrients and glucose (or energy) from the stomach and intestine to muscles and tissues, carting away CO2 and metabolic waste as it goes. Each of these functions is carried out by different components of our blood, including:

• Red blood cells: These workhorse cells include hemoglobin and iron and deliver oxygen throughout your body. They’re the most plentiful type of blood cell and make up about 40 percent of one’s total blood volume. 

• White blood cells: These are the largest and least abundant blood cell. Their job is an important one: fighting off infections and disease.

• Platelets: These tiny disc-shaped cells help maintain our blood’s consistency and work together to coagulate, or clot, to prevent bleeding. 

• Plasma: Making up 55 percent of blood’s volume, plasma is the liquid part of blood that enables it to flow throughout our bodies. Plasma is made up of water, salts and enzymes and carries nutrients, hormones and protein throughout the body. 

The circulatory, or cardiovascular, system is the complex organ through which blood flows via vessels. In short, arteries take oxygen-rich blood from the heart, while veins carry oxygen-depleted blood from throughout the body back to the heart. Capillaries, the smallest type of blood vessel, are tasked with exchanging nutrients and oxygen from the blood to tissues. 

What Your Blood Reveals

 “A drop of blood travels your whole body, so it provides a unique window into your overall health,” says Dr. McEvoy. By drawing just three to 10 milliliters of blood—equal to about one to three teaspoons—your doctor can gauge your overall health status and screen for a host of ailments. The most common blood test ordered, and the one you typically get as part of a well visit, is the complete blood count (CBC). 

A CBC does just that—it counts your red blood cells, white blood cells and platelets. Cell counts that are outside of normal levels can indicate a range of issues, including anemia, infection or bone marrow issues. “If a cell count is off, we investigate to determine what’s causing the imbalance,” says Dr. Ferguson. 

CBCs are just the tip of the blood-test iceberg. There are dozens of diagnostic blood tests that examine specific elements carried within blood—including nutrients, hormones and cholesterol—or that aim to gauge the health of a certain organ. These may be ordered if a CBC reveals unexpected counts, or if a person has concerning symptoms without a clear underlying cause.

Understanding Blood Pressure

While analyzing the components of blood via blood draw is one piece of the puzzle, measuring the rate at which blood flows through your vessels is another. That’s why blood pressure readings are conducted at any health examination. When a technician puts the cuff around your arm and pumps it up, they’re measuring both the pressure inside your arteries when your heart beats (systolic pressure) and between beats (diastolic pressure). A healthy reading is under 120/70 mmHg (systolic/diastolic). 

When blood contains too many lipids—which are fats and fat-like substances, including cholesterol—blood vessels can harden over time. This hardening makes vessels less pliable, which can decrease blood flow through and increase the pressure within. When blood pressure readings consistently read 140/90 or higher, hypertension (or high blood pressure) is diagnosed. Uncontrolled hypertension can lead to blockages within the circulatory system that can eventually cause a heart attack—which occurs when blood can’t flow through part of the heart—or stroke, when blood can’t reach part of the brain. 

Ailments of the Blood 

While information from our blood can serve as a red flag for issues affecting other organs, our blood itself is vulnerable to certain diseases and disorders. Some are genetic (meaning our DNA predisposes us to the condition) and/or hereditary (the condition is passed from one generation to the next). Other conditions are influenced by lifestyle factors like diet, activity, age and more. The most common disorders of the blood include: 


A low red blood cell count is called anemia. Specific types include iron deficiency and sickle cell anemia. In some cases, anemia can be a sign of larger issues. For example, anemia may manifest from blood loss from the colon—often an indicator of colon cancer. In all cases, oxygen delivery is compromised, causing extreme fatigue. Treatment is based on the determined cause. 

Clotting Disorders

When we’re injured, clotting is a good thing—our platelets assist in responding to an area of tissue damage to stop us from bleeding. Clotting disorders affect this healthy response. 

In hemophilia, a hereditary condition, blood doesn’t coagulate, or clot, as it should, putting the sufferer at increased risk for severe bleeding. 

In other conditions, such as antiphospholipid antibody syndrome, internal clots form when they shouldn’t. If uncontrolled, this type of clotting issue can lead to major problems including heart attack, pulmonary embolism (a life-threatening blockage within the lungs’ arteries) and more. Dr. Ferguson likens clotting to a car crash. “If  there’s a wreck on the side of the road—like a clot in a small or superficial vein—that only causes problems for the people in the cars involved. But if there’s a wreck on I-526—the equivalent of a deep vein in your leg—it causes a problem for everybody in Charleston (i.e., your whole body).” A large clot in your leg can make it to your lungs, causing a pulmonary embolism. A clot in an artery or in your heart can move to your brain, causing a stroke. 

Treatment varies based on the type of disorder, but often includes medication, regular blood tests to monitor the condition and frequent physical activity. Blood that sits too long in one place has a higher chance of clotting, so the more you move, the better. 


One of the primary nutrients our blood carries throughout our body is glucose, a simple sugar we use to make energy. Our bodies use a hormone called insulin to deliver the glucose to our cells. In people with diabetes, a lack of insulin causes glucose to accumulate in the blood, which can damage blood vessels, kidneys and eyes. Sufferers feel tired because their muscles aren’t receiving the energy they need. “Your muscles are saying, ‘Hey, we need more glucose!’ even though you have a ton of it, and the problem snowballs,” explains Dr. Ferguson. 

There are two primary types of diabetes and treatment varies based on type. Type 1 is a hereditary disease, typically diagnosed during childhood, in which the body does not produce insulin. To treat it, an outside insulin source is injected, thus regulating blood glucose levels. 

Type 2 diabetes develops over time—diet and lifestyle are important factors—and manifests as insulin resistance. A poor diet 

can lead to excess insulin production, which eventually causes the body’s cells to ignore it. At a certain point, no matter how much insulin is made, cells don’t receive the glucose. The most common treatment is metformin, a drug that makes the body more sensitive to insulin so that glucose can be absorbed. Though there is no cure, people with type 2 diabetes can reverse the condition and improve blood sugar levels with changes to diet and activity level.


Cancer is essentially uncontrolled cell growth. In leukemia, or cancer of the body’s bone marrow, the body produces too many white blood cells. This crowds out red blood cells and platelets and can lead to organ failure. Treatment may include chemotherapy and radiation, among other therapies. 

Healthy Body, Healthy Blood

For patients diagnosed with certain blood conditions—like diabetes and clotting—regular blood testing is key. People with diabetes typically check their blood glucose levels multiple times a day using a blood glucose meter. This draws a spot of blood via finger prick and reveals glucose level instantly. A clotting patient may have their blood drawn at a lab or at home once every week or two. 

For those without a blood disorder, regular lab work is an important preventative health tool. And by all means, “If you have a symptom like fatigue, or if you just feel ‘off,’ talk to your primary care doctor about whether a blood test would be appropriate. He or she may recommend one to look for an issue like a vitamin deficiency or thyroid disorder,” says Dr. Ferguson.

To help ensure your blood, circulatory system and whole body stay as healthy as possible, pay attention to lifestyle choices you make day in and out. “Blood health depends on a nutritious, balanced diet,” says Dr. McEvoy. Avoid diets high in sodium and cholesterol as they can lead to high blood pressure, among other ailments. And to support the health of your red blood cells, eat plenty of iron-rich foods, including spinach, fish and beans.

Next, get active. When blood pumps faster during cardiovascular exercise, it speeds oxygen exchange in the blood, ultimately helping to lower heart rate and blood pressure. “Getting 150 minutes of physical activity per week gives you the same benefit as a single blood pressure medication with none of the side effects,” says Dr. Ferguson. That doesn’t have to be strenuous exercise either. 

“We’re looking for moderate intensity,” he says. “It can be walking at a pace that’s fast enough to break a sweat at room temperature.” Another blood-boosting benefit of physical activity? Studies show that exercise can actually reverse clot formation. 

Finally, avoid tobacco and excess alcohol consumption, both of which are risk factors for a host of blood-related ailments, from hypertension to diabetes to clotting. 

When we eat a balanced diet, give our heart the activity it needs and steer clear of outside elements known to cause harm, we’re able to keep our blood—and thus, our whole bodies—in the healthy shape that we deserve.

Brian Olson 

CONDITION: Antiphospholipid antibody syndrome (a clotting disorder)

HIS STORY: In August 2019, West Ashley resident Brian Olson developed a blood clot in his eye. “I experienced some bright flashes in my right eye and then had the sensation of a dark shade being lowered over part of my vision,” he explains. After testing, he was diagnosed with antiphospholipid antibody syndrome, a clotting disorder. To ward off future clots, Brian takes a blood thinner daily and tests his blood every week or two. He works with Roper St. Francis Healthcare affiliated doctors John Ferguson (primary care) and Ryan Kalinsky (hematology) to manage the condition. “My doctors have encouraged self-management in many ways,” says Brian. “They led me to an at-home self monitoring system, which I appreciate because I don’t have to go in for labs all the time.”

Traci Ray 

CONDITION: Type 1 diabetes
HER STORY: North Charleston resident Traci Ray, 56, pictured here on left, was diagnosed with type 1 diabetes when she was 10 years old. “Diabetes guides most of my decisions during the day,” she says. “I decide what I am going to eat for each meal after I look at my blood sugar levels.” Traci—who is a Roper St. Francis Healthcare affiliated diabetes nurse educator—uses an insulin pump and a Dexcom G6 continuous glucose monitor (CGM) to track her blood sugar. “Checking blood sugar levels is one of the ‘health chores’ that we ask people to do,” she says. “It can help someone avoid the diabetes complications that they fear. Also, blood sugar levels tell people if they are moving in the right direction with their diabetes care.”

Be A Hero

According to The Blood Connection, every two seconds, someone in the U.S. needs blood, whether due to a traumatic accident, a chronic disease, cancer treatment or surgery. Blood transfusion—or the process of adding blood to the body of a person in need—occurs roughly five million times in the U.S. every year, and is possible thanks to blood donors. 

A typical blood donation totals roughly one pint. That’s less than 10 percent of the average American’s total blood volume and is quickly replenished by the body. Our bodies can replace plasma (the liquid part) from a pint of blood in 48 hours; red blood cells reproduce within four to eight weeks. 

Donating blood takes about an hour, with the actual blood draw lasting just 10 to 15 minutes. To ensure your blood is eligible, you’ll answer several questions about recent travel and your health history. After you donate, your blood is tested for viruses like hepatitis, HIV and COVID-19. Once a sample is cleared, blood banks distribute it for use during life-saving transfusions. 

Donating blood is extremely low risk. Some people may experience a reaction to the sight of a needle, while others may feel light-headed. The latter can be treated with extra water and food intake. To help, free snacks are typically dolled out at donation sites. 

The Blood Connection is Roper St. Francis Healthcare’s blood donation partner. They have mobile donation sites that make donating blood quick, easy and safe. Visit to find a mobile drive near you. 

See Blood? Here’s When to See a Doc

When you scrape a knee or cut a finger, blood is expected. But if you spot blood in one of the following places, make an appointment with your doctor as testing may be needed