The Top 10 Medical Advances in History

Osmosis Team
Published on Jul 10, 2023. Updated on Mar 28, 2024.

A variety of important medical discoveries have revolutionized healthcare throughout history, radically transforming the diagnosis, treatment, and prevention of disease. In today’s Osmosis blog, we’re sharing our top picks for medical advancements that have contributed to the overall health and wellness of humanity.

Throughout history, medical advances (particularly in the 19th and 20th centuries) have revolutionized how physicians understand, diagnose, and treat disease. These advances have directly contributed to the significant rise in global life expectancy, nearly tripling it from just 28.5 years in 1800 to 72.6 years in 2019.

We invite you to take a look at our top ten picks for medical advances that have had the most profound impact on humanity and our long-term health.

Illustrated germ angry at antibiotics

1. Antibiotics: Revolutionizing the treatment of infections

The discovery of antibiotics stands as one of the most critical advances in medical history. They were discovered in 1928 when Alexander Fleming returned home from vacation to find a petri dish on his workbench filled with a strain of mold that was not only thriving but also limiting the growth of bacteria. 

The true significance of Fleming's discovery became apparent more than a decade later when penicillin, the active substance in the mold, was isolated in 1940. The effectiveness of the antibiotic was immediately evident during World War II in the treatment of battle wounds, saving the lives of an estimated 200,000 soldiers. Penicillin remains a primary treatment for bacterial infections and has paved the way for developing numerous other antibiotics. 

In addition to the treatment of infectious diseases, the existence of antibiotics meant that procedures like open-heart surgery, organ transplants, and chemotherapy could become a reality. Many view the years between 1940 and 1960 as the "golden era" for antibiotics, with a good portion of them developed over that period and still in use today.

Illustration of viruses and vaccines in both pill and injection form.

2. Vaccines: Preventing deadly diseases

The fact the word vaccine derives from the Latin word for cow is no coincidence, given Edward Jenner's discovery in 1776. He observed milkmaids who'd been exposed to the relatively mild cowpox virus developed an immunity to the more serious smallpox virus. His discovery led to the development of the smallpox vaccine, and 179 years later, in 1977, smallpox was eradicated (and remains the only disease ever to be entirely eradicated).

Despite significant advances, the modern vaccine wasn't developed until 1950, when a rampant outbreak caused parents to isolate their children to prevent them from catching polio. Governments spent millions researching a vaccine, and, in 1952, Jonas Salk and his team at the University of Pittsburgh delivered. Perhaps even more extraordinarily, Salk did not file a patent, saying "[the vaccine] belonged to the people." Due to his kindness, polio has just about been eradicated globally, with a handful (six) cases in 2021 and two as of May 2023. 

From these origins, vaccines were developed for many serious illnesses, such as tetanus, diphtheria, measles, meningococcal, tuberculosis, chicken pox, and HPV, to name but a few. The development of vaccines has prevented countless deaths and brought many potentially deadly diseases under control, including COVID-19 and its many variations.

A group of health professionals in surgery with a patient receiving anethesia.

3. Anesthesia: Transforming surgical procedures

Prior to the mid-1800s, surgical procedures were limited due to the excruciating pain patients experienced. This changed in 1846 when William TG Morton used ether to anesthetize a patient for surgery. The drugs used to anesthetize patients for surgery have come a long way since these early days. Techniques have also been refined and, when used in combination with new technologies, have resulted in significant gains in patient safety

Global standards have been established for monitoring hemodynamics, vital signs, and respiration, among others. Technology helps assess the depth of anesthesia, while algorithms help assess patient comfort levels. As a result, many surgical procedures that would not have been possible without these developments have become relatively routine.

Image of a doctor reading an x-ray.

4. X-rays and Medical Imaging: Advancements in non-invasive diagnostics

Before the advent of medical imaging, physicians relied on their sense of touch, observations, and the patient's account of their symptoms to diagnose them. The discovery of X-rays by William Conrad Roentgen in 1896 revolutionized diagnostic medicine based on his experimentation with electric currents and glass cathode-ray tubes. The potential of his discovery in the diagnostic process was immediately recognized, with Glasgow Hospital opening its first radiology department just a year later.

Ultrasound uses high-frequency sound waves to create an image. In 1956, its usefulness in the medical field was recognized and found particularly useful in prenatal monitoring and detecting pelvic and abdominal conditions. This discovery was followed by computed tomography (CT) in 1967 and magnetic resonance imaging (MRI) in 1973. 

As technology has advanced, so have the images these tools produce. Medical professionals can now obtain detailed images of what's happening inside a body, allowing them to confidently diagnose conditions, such as cysts, tumors, and other abnormalities non-invasively. The ability to visualize the internal structures and organs is vital to the early diagnosis and treatment of many brain, heart, lung, liver, and kidney conditions.

Illustration of a variety of germs under a microscope

5. Germ Theory: Small changes make a big impact

The introduction of anesthetics in 1844 meant that doctors could attempt longer and more complex procedures. However, post-surgery infection rates were soaring, along with mortality rates, limiting progress since scientists had no explanation for what caused infection until French microbiologist Louis Pasteur developed germ theory in 1861.

Pasteur's work proved that infections resulted from microorganisms or pathogens entering the body. Joseph Lister (see #9 in our list) applied Pasteur's theory to surgical infections (despite being labeled "mad" by many of his colleagues). As infection rates improved, his peers had to acknowledge the value of his approach. 

In the century and a half since Lister's application of Pasteur's work, a variety of diseases that had previously killed thousands, such as the plague, dysentery, and typhoid fever, have all been brought under control through understanding and applying germ theory.

Representation of an adult donating some of their liver to an infant for organ transplantation.

6. Organ Transplantation: Saving lives through organ replacement

The first successful kidney transplant was performed by Joseph Murray in 1954. While it had been attempted before, this was the first time the patient survived the surgery. By 1968, surgeons successfully completed pancreas, liver, and heart transplants, with the first heart-lung transplant in 1981.

Although these procedures extended the recipients' lives, rejection was still a significant problem, limiting the number of transplants. Medical researchers began to focus on developing immunosuppressant medications. The discovery of cyclosporine proved to be a major breakthrough in 1984, opening the door for more challenging transplants involving live donors. 

As of September 2022, US doctors have completed 1 million transplants and performed more than 40,000 transplants annually, extending lives and improving the quality of life for numerous patients. 

Geneticist working on a genetics project.

7. Genetic Engineering: Unlocking the secrets of life

The discovery of the double helix structure of DNA by James Watson, Francis Crick, and Rosalind Franklin revolutionized molecular biology. The development of a map of the human genome has been vital in predicting and understanding the incidence of many diseases. While this information is already used to screen and create interventions for at-risk groups for conditions for which they may have a predisposition, the potential is even greater, with the possibility of personalized medicine and gene therapies close to becoming an everyday reality.

As researchers have learned more about the human genome, they've developed techniques to manipulate it, which has given rise to gene therapy and genetic engineering. Although it's still very much in its infancy, the potential for medicine is huge, with scientists able to insert recombinant DNA into organisms to replace "faulty" sections and thereby reduce or remove genetic predispositions.

A human heart during open heart surgery, with clamps surrounding it.

8. Heart Surgery: Pioneering cardiovascular interventions

The first coronary artery bypass graft (CABG) was performed by Dr. Rene Favaloro in 1967 when he took a vein from his patient's leg and used it to bypass a blocked coronary artery. This innovative procedure restores blood flow to the heart muscle and relieves the symptoms of angina and the likelihood of a heart attack.

In the last 25 years, doctors have developed various minimally invasive cardiac procedures to treat heart disease, negating many risks associated with open-heart surgery. In addition, using robotics to assist in cardiac procedures has further helped decrease surgery times, improve patient comfort, and reduce recovery times. 

Patients who have undergone a CABG and made it through the first month following the surgery have a life expectancy similar to that of the general population. In the US, cardiovascular interventions have contributed to the death rate from heart attacks falling from 87 per 100,000 in 1999 to 38 per 100,000 in 2020, illustrating the importance of this still-evolving field.

An illustration of a variety of antiseptics in bottles and antiseptic pads.

9. Antiseptics: Enhancing Sterilization and infection control

Joseph Lister's development of antiseptics significantly improved infection control in surgery and beyond. Concerned with the high mortality rate following surgery, Lister began experimenting with different techniques to prevent infection, developing the antisepsis system in a home laboratory while working with his wife and assistant, Agnes.

The aseptic technique minimizes the risk of outside contaminants and is at the heart of infection control in all areas of medicine. Handwashing between patients is now so commonplace that it seems hard to believe it was not always the case.

A person checking their glucose levels with a meter and insulin in a syringe.

10. Insulin: Saving millions of lives daily

Thanks to insulin, a diagnosis of type I diabetes is no longer a death sentence, but prior to 1922, children diagnosed with type I diabetes were expected to live for just one and a half years, and adults less than ten. The discovery of insulin by Sir Frederick G Banting, Charles H Best, and JJR Macleod at the University of Toronto meant that those with diabetes could live a relatively normal life.

James Collip joined the team to help purify the insulin. Fourteen-year-old Leonard Thompson, who was dying from Type I diabetes, was the first patient to receive this lifesaving treatment. After his second dose, his blood glucose levels normalized, with no side effects observed.

The discovery of insulin is especially pertinent today, with the significant global increase in cases of type II diabetes. Insulin helps control blood glucose levels in those with diabetes and delays the onset of its debilitating symptoms, increasing the life expectancy of diabetes patients and saving health systems billions.

Illustration of a microphage virus, a 3D printer, and a robotic arm with a spy glass looking for AI.

Honorable Mentions

Several other medical advances came close to making our top ten and definitely deserve some recognition!


Hippocrates considered the connection between the environment, host factors, and disease development around 400 BC, and Joaquín de Villalba first used the term epidemiology to explain these connections in the late 1700s. However, it was John Snow who meticulously mapped the incidence of cholera in London in 1854, tracing the source of the infectious disease to specific water pumps while illustrating the importance of applying statistical analysis to the outbreak of disease, outcomes, and behaviors. 

3D Printing

When Chuck Hall first developed 3D printing in 1983, few could have imagined its medical applications. Thirty years later, the technology enables scientists to print the scaffolds for organs, prosthetic limbs, and medications. With the technology still very much in the early stages, the future applications of 3D printing in healthcare have incredible potential.

Artificial Intelligence (AI)

Artificial intelligence is already making its mark in many aspects of medicine. It's assisting medical professionals in diagnosing and treating illness, with its potential seemingly limitless to the extent that it's likely to be a permanent fixture on future top 10 lists. The current challenges involve overcoming the ethical issues around how much control machines have over the diagnostic and treatment process and ensuring accuracy.


It takes many pieces of a puzzle to see the bigger picture. While every little piece of knowledge improves our ability to diagnose and treat illness, these top ten medical advances have more than left their mark by drastically improving the life expectancy and health outcomes of millions of people. With so many rapid technological advancements, scientists can better understand, investigate, and develop treatments, building on these discoveries to improve health outcomes globally.