Health and Disease

Donated Blood: How Is It Collected? Where Does It Go?

By Yesha Shukla

Published 11:53 EST, Mon November 1st, 2021


Donating blood is common and a highly beneficial thing to do. Many selfless individuals donate their blood yearly which benefits sick patients all around the world. Each year, an estimated 6.8 million people in the United States alone donate blood, resulting in their collection of 13.6 million units of whole blood and red blood cells. However, many often question how exactly this donated blood is collected, processed, stored, and used which is exactly what this article aims to investigate.

Types of Blood Donations

The standard types of blood donation must be first understood before answering such a question because the type of blood being donated heavily influences the method in which it is collected. Beginning with a standard blood donation, this consists of plasma, red and white blood cells, platelets, antibodies, and other components. Plasma, also known as plasmapheresis, is another type of donation that separates plasma from the other components. This is done using a special machine and red blood cells are returned to the donor in cycles throughout the donation. Plasma is often given to individuals in emergency and trauma situations to help stop bleeding. Lastly, platelet donation–or plateletpheresis–is conducted in a similar way to plasma donations, but red cells and plasma are returned to the donor. These are typically given to individuals with clotting problems, cancer patients, or those who will have organ transplants or major surgeries. Additionally, a less common donation includes autologous which occurs before operation or transfusion where a person donates blood for their use. A directed or designated donation is also possible where a donor gives blood that is intended for a specific person to use.

How Much Blood Can Be Given?

It is crucial to understand exactly how much blood an individual can give before determining collection procedures as well. Healthy adults aged 18-75 are especially encouraged to donate as well as those with O negative blood because it can be given to anybody–of any blood type–if necessary. Regular donations collect around 470 mL of whole blood, which is 8% of an adult’s average blood volume. The body replaces this amount within 24 to 48 hours and replenishes red blood cells in 10 to 12 weeks. Additionally, individuals can donate whole blood every 12 weeks and plasma every 2 weeks.

How Is It Collected?

Now that the necessary basic information on blood collection is known, the specifics on how exactly it is collected can be investigated. First, pre-screenings are conducted to ensure the donor’s blood is healthy and will not damage a recipient. All donated blood is screened for blood-borne diseases–HIV, Hepatitis, Syphilis–and the donor must not suffer from a cold, flu, or any other illness at the time of donation. They must weigh at least 50kg and have a normal temperature and blood pressure. In the times of COVID, they must also be screened for the virus.

Taking blood is also a relatively simple process for regular blood donations. A blood pressure cuff or tourniquet is placed around the upper arm to fill a donor’s veins with more blood. A phlebotomist will then cleanse the area on the arm with an antiseptic and insert a sterile needle for the blood draw. This sterile needle is attached to a thin plastic tube and a blood bag. Once the needle is in, the donor should tighten their fists several times to help blood flow from the vein. Initially, blood is collected into tubes for testing and is then allowed to fill the blood bag. This process takes about 8 to 10 minutes and can be done sitting upright or laying down. When approximately a pint of blood is collected, the donation is complete and staff will remove the needle, elevate the donation arm, and apply slight pressure to promote clotting before bandaging the arm.

The process for platelet donations is however slightly different. Though the same pre-screening and sterile needle method still exist, a needle and plastic tube are connected to both arms. For such donations, an apheresis machine is used which collects a small amount of blood and separates the red cells, plasma, and platelets. It then returns the rest of the blood through the donor’s other arm and this cycle is repeated several times over about 2 hours.

How Is Blood Transported Post-Draw?

Directly after blood is taken, the donation, test tubers, and donor records are labeled with an identical bar code label. The donation is kept in ice before being taken to a processing center and the test tubes go to the lab. At the processing center, information about the donation is scanned onto a computer database before further steps are taken to prepare the blood to be shipped out to hospitals. Most whole blood donations are spun in centrifuges to separate them into transfusable components–red cells, platelets, plasma. Plasma may be processed into components–cryoprecipitate–which helps control the risk of bleeding by helping blood to clot. The red cells and platelets are leuko-reduced, meaning white blood cells are removed to reduce the participant’s possibility of reacting to transfusion. Each component is then packaged as a “unit” which is a standardized amount that doctors will use when transfusing a patient.

In parallel with all of this, the test tubes arrive at a testing laboratory where a dozen tests are performed to establish the blood type and test for infectious diseases. The test results from this are electronically transferred to a processing center within 24 hours and if results are positive, the donation is discarded.

When test results are received, units suitable for transfusion are labeled and stored. Specifically, red cells are stored in refrigerators at 6 degrees Celsius for up to 42 days, platelets are stored at room temperature for up to 5 days, and plasma and cryo are frozen and stored in freezers for up to 1 year. When blood is needed at hospitals, it is available for distribution 24/7. Hospitals typically keep blood units on their shelves, but some often call to receive units in times of urgency.

How Does Blood Transfusion Occur? What Products Are Made From Blood?

After the blood donation has reached the hospital, it is removed from storage and given to a patient in need through an intravenous line. This is a tiny tube that is inserted into a vein with a small needle and the transfusion process takes about 1 to 4 hours in total depending on the amount of blood needed.

Additionally, specific products can also be made from blood. From whole blood, red cells can boost the oxygen-carrying abilities of a patient’s blood. Platelets can clot blood assisting in those recovering from a severe hemorrhage. Lastly, plasma can be used in treating people with burns, cancer, and protecting people with brain and nerve diseases. Plasma contains antibodies and other important proteins used to make human immunoglobulin, human albumin, human coagulation factor IX, and many other specific products.


Blood donations travel a long way and though it only takes a couple of minutes to donate whole blood, a pint of blood could save a life in need. Due to the lack of donations during the pandemic, blood donations are at an all-time low; thus, individuals should donate blood if they can and are healthy enough to do so.

Yesha Shukla, Youth Medical Journal 2021


American Red Cross. (n.d.). The Blood Donation Process. Blood Donation Process Explained | Red Cross Blood Services. Retrieved October 2, 2021, from 

American Red Cross. (n.d.). What Happens to Donated Blood. American Red Cross | Blood Services. Retrieved October 2, 2021, from 

Australian Red Cross Lifeblood. (2021, June 4). Blood donation. Blood donation – Better Health Channel. Retrieved October 2, 2021, from 

Community Blood Center. (n.d.). Blood Donation process. Community Blood Center. Retrieved October 2, 2021, from 

Mayo Clinic Staff. (2021, March 4). Blood donation. Mayo Clinic. Retrieved October 2, 2021, from 

Health and Disease

Poor Eyesight: Why Does It Happen and What Makes It Better/Worse?

By Yesha Shukla

Published 11:26 EST, Thurs October 21st, 2021


Poor eyesight is becoming a common, widespread issue across the globe. Individuals are developing problems related to vision ranging from severe eye conditions to slight impairment more often than ever. Though some visual impairments are not correctable, the most common forms–such as errors of refraction–are. However, before such treatments for poor eyesight can be investigated, a solid understanding of where vision impairments stem must be understood.

Understanding Poor Eyesight 

In comparison to the other four key senses, a larger part of the brain is dedicated to vision, making it one of the most highly developed sensory organs. This not only makes vision a key component of the body, but also one of the most vulnerable. 

The most common forms of vision impairment are errors of refraction, which are when light rays fail to focus inside the eye and, thus, transfer blurry images to the brain. Examples of errors of refraction include nearsightedness, farsightedness, and astigmatism. However, not to worry, such vision impairments are typically correctable using glasses, contact lenses, or refractive surgery- LASIK, Photorefractive keratectomy, or Implantable Collamer Lenses.

Furthermore, another common form of poor eyesight is eye strain. This occurs when individuals overuse their eyes for an extensive period of time and can also be due to an uncorrected refractive problem. Eyestrain may occur while performing distant visual activities or prolonged focusing (driving, watching a movie, reading, computer use, etc). Eyestrain is not common among children due to their flexible focusing capacity, however, if the eyes are not given adequate rest, adults may experience its effects through headaches, brow aches, eye fatigue, or a pulling sensation. Additionally, experiencing these symptoms while wearing glasses could indicate the need for an eye prescription change. 

Other forms of vision problems often relate to eye disease. Examples of such include retinal detachment, macular degeneration, cataracts, and glaucoma. These can lead to blurry or defective vision and require surgery for correction.  

How Common Is The Problem? 

These vision impairments are not uncommon among individuals worldwide. At least 2.2 billion people have poor eyesight, 1 billion of which could have been prevented or have yet to be addressed. Such unaddressed vision impairments are most common in low and middle-income regions as the statistics report about 4 times as many cases like that of high-income regions. In some areas, eye care needs are greater in rural areas but the services are in urban hospitals, leading to low accessibility. Furthermore, eye conditions are projected to worsen in the future due to the aging population, genetics, ethnicity, lifestyle, and environmental factors. Thus, it is crucial to limit the chance of such a situation by understanding what makes eyesight worse and what can help it improve.   

What 4 Key Practices Impact Vision Negatively? 

An excess amount of screentime is one of the most widely known factors that impair vision. According to the American Optometric Association (AOA), the average American spends seven hours a day on their digital device and 58% of adults have experienced digital eye strain as a result. Additionally, according to Common Sense Media’s 2019 Census, eight to twelve-year-olds spend five hours on digital media. These individuals, especially if they spend more than two continuous hours using a digital screen, have a much greater risk of eye strain. This can be very damaging to the eyes and is often the most common cause of worsening vision problems.

Wearing contact lenses incorrectly is another common cause of impaired vision. The AOA found that 90% of the 45 million contact lens wearers in the US don’t follow proper hygiene instructions. ⅓ wear non-overnight contacts while sleeping, which can lead to inflammation, dry eye, pain, blurry vision, and light sensitivity. These all deprive the eyes of oxygen and can worsen eyesight as a whole. Furthermore, many also wear contact lenses in the shower or pool, leading to bacteria getting into the eyes and ultimately causing an infection. 

Next, not wearing sunglasses to protect from UV radiation causes both long and short-term damage. Just one day at the beach without eye protection can lead to photokeratitis– or sunburn of the eye– which can be temporary, but very painful. Long-term damage from UV rays can lead to the formation of cataracts and pterygium which causes abnormal covering on the white of the eye, impairing vision for a lifetime. There is also a risk for cancer on the eyelids, the skin around the eye, or the eye itself. Additionally, children’s eyes are much more vulnerable to damage from sunlight because their eye lenses cannot filter such UV rays easily, causing damage to the retina. The AOA reports that the average child is exposed to three times the annual UV exposure of an adult and 80% of such exposure occurs before the age of 20. 

Finally, the heavy use of eye drops is a common cause of vision impairment. Though it may seem to be helping the eye, this washes away natural tears. Prolonged use of eye drops can cause dependency on them, leading to the eye being unable to self-moisturize and protect its delicate layers. The glands can also get clogged because they will not secrete the proper oils to hold tears in place. In relation, whitening eye drops used to get red out of the eye can decrease blood flow, preventing oxygen from getting into the eye. In turn, the blood vessels can grow enlarged and become even redder due to their inability to deliver oxygen. 

What 4 Key Practices Impact Vision Positively?

Just as crucial as understanding what worsens vision is understanding what can better it. However, there is no specific method for improving vision directly without the use of corrective measures. This is because eye shape determines the level of refractive error and this cannot change with exercises or eye training. Thus, there is only one possible way to improve eyesight: to naturally improve the way in which the brain and eyes work together by improving eye health and, therefore, vision as a whole.

Eating a balanced and healthy diet rich in antioxidants and vitamin A–such as leafy vegetables, carrots, or fish–is incredibly important. Such foods slow down age-related vision loss by strengthening connections between the brain and the eyes. Getting enough sleep can also aid in bettering vision as by being tired, the eyes get strained easily and feel dry and gritty. Exercising regularly has shown signs of enhancing circulation of blood and oxygen flow to the eyes, decreasing dry eyes, and preventing vision loss. Protecting the eyes from UV rays and practicing good eye hygiene are also especially important. Washing the hands and face thoroughly and regularly and keeping cosmetics and other chemicals outside of the eyes can prevent potential damage. Lastly, taking breaks from screen time is essential. The AOA suggests looking 20 feet away every 20 minutes for 20 seconds at a time to prevent eye strain. 


As a whole, eye conditions are very common among the current population and the best thing that can be done to prevent them is to make healthy life choices from a young age and see the eye doctor regularly. Taking care of the eyes is crucial and must be prioritized more often to avoid more individuals causing damage to their vision. 

Yesha Shukla, Youth Medical Journal 2021


Seltman, Whitney. “Understanding Vision Problems — the Basics.” WebMD, WebMD, 7 Feb. 2020,

All About Vision Editorial Team. “7 Everyday Things That Can Hurt Your Eyes.” All About Vision, All About Vision, 7 Sep. 2021,

NVISION. “How to Improve Eyesight Naturally (& Safely).” NVISION Eye Centers, NVISION, 23 Dec. 2020,

World Health Organization. “World Report on Vision.” World Health Organization, World Health Organization, 8 Oct. 2019,