Whether it's the technology that allows us to peer deep into the body or medicines that extend the lives of those with chronic diseases, it's easy to see how advances in health and medicine have touched the lives of nearly every person on the planet.
Yet considering the ubiquitous nature of these developments, it is easy to see how many people take for granted the technologies and practices that, at one point or another, almost certainly saved their own lives or the lives of people they've loved.
The list below encompasses 10 advances in health and medical practices that have changed -- and in many ways continue to change -- the world today.
Throughout history, communicable diseases have had a tremendous impact on human history. So too, then, has the development of one of the most effective ways to defend against rampant viral infection -- vaccination.
Dr. Edward Jenner first introduced the idea of vaccinations in 1796, when he successfully prevented a young English boy from getting smallpox.
The concept of vaccination was propelled further by scientists such as Louis Pasteur, and in the modern era, when large groups of soldiers were successfully vaccinated in World War I and II against such diseases as tetanus, diphtheria and typhus.
"Polio vaccine is one that people think of because it had such an impact," said Dr. Jeffrey Baker, director of the history of medicine program at the Duke University School of Medicine.
But from the global health standpoint, Baker said Jenner's introduction of the smallpox vaccine may have had an even more significant impact in terms of lives saved.
Without a doubt, surgery used to be a much graver proposition than it is today. One of the chief reasons for this is that before the middle of the 19th century, anesthetic simply wasn't an option.
That changed Oct. 16, 1846, when William T.G. Morton demonstrated the mysterious wonder of ether -- a substance powerful enough to dull the pain and agony that had long been associated with surgery.
But while anesthetic was a great advance in and of itself, another advance that occurred at roughly the same time may have been even more beneficial -- antisepsis, or the creation of a sterile surgical environment.
"Anesthetic made it possible to operate on a patient without pain," Baker notes, "but without antisepsis they'd die anyway."
Put them beside surgical advances and other cutting-edge technologies, and public health measures don't look so sexy. But the fact is that clean water and sanitation have likely saved millions -- perhaps billions -- of lives since they were widely implemented in the 19th and 20th centuries.
"It's something that's so important around the world and in America," Baker said. "It used to be that 15 percent of infants would die, and the biggest reason for this was diarrhea brought about by unclean water and milk."
Clean water and public health measures dramatically cut down the incidence of such deadly water-borne diseases as cholera and improved sanitation, drastically lowering the health impacts of parasitic infections and other health conditions related to the environment.
As with vaccination, the advent of antibiotics hailed a new era in the treatment of communicable disease.
Interesting, then, that the concept of antibiotics may have been uncovered accidentally. In 1928, Sir Alexander Fleming left a petri dish of Staphylococci bacteria uncovered and later noted that the bacteria had been killed by a mold.
Upon further studying the mold, he discovered it was from a family called Penicillium notatum. Others soon saw the potential uses of what later came to be known as penicillin.
Today, antibiotics are used to treat a plethora of bacterial illnesses. And today, researchers are developing antivirals -- most notably, the AIDS-fighting antiviral AZT -- to deal with a host of viral illnesses as well.
Arguably, few developments have had as profound a social impact as the introduction of the birth control pill -- though its path to widespread use has been a rocky one.
Although the Federal Drug Administration approved contraception as safe in the early 1960s, it only became legal for married couples in 1965 and for unmarried couples in 1972.
But because of the Pill, countless women have been given control over their own fertility -- a concept that created a social revolution.
"Thinking about how it has transformed women's lives, in terms of family planning and the entry of women into the work force, its impact has been significant indeed," Baker said. "It was the first-ever lifestyle drug. It's not treating a disease, but it was making life better for women."
Heart disease remains at the top of the list of the country's killers. Despite this, numerous important advances in its treatment have made a considerable impact, extending and improving the lives of its sufferers.
Not the least of these advancements is surgeons' ability to operate on and repair the heart -- without putting the patient at an unreasonable amount of risk.
"Maybe the breakthrough moment was the rise of the heart-lung bypass, which made it possible to operate on the heart for more than just a few minutes at a time," Baker said. "This was followed by coronary artery bypass grafting, which is, I believe, a most important procedure."
Another development largely unnoticed by the public at large, the advent of the randomized controlled trial -- what many refer to as the gold standard of medical research -- gave medical researchers an important tool in determining which treatments work, and which do not.
Randomized trials are conducted by dividing patient populations into two groups, where one group receives the intervention to be studied while the other does not. Examining the differences between groups in these types of trials has ushered in an era of evidence-based medicine that continues to guide clinical practice on a daily basis.
"I think this is huge," Baker said. "This is really what's changed how we deal with cancer and lots of other disease, too. In the future we'll look back at this as a huge step forward."
Before the development of radiologic imaging technologies, beginning with the use of the X-ray, doctors were usually relegated to looking only for external signs of injury or damage.
Today, the ability to peer inside the body and determine the cause, extent, or presence of disease has revolutionized the very way medicine operates and has saved countless lives in the process.
Much of the initial work surrounding the discovery of X-rays was done by Roentgen, a German physicist in the late 1800s. Initially, they were viewed as an invasion of privacy rather than a life-saving tool.
Its utility was soon realized, however, and many additional imaging technologies eventually followed.
"CT scans didn't come into the picture until the 1970s," Baker said, adding that this technology was brought to us by the company BMI -- the same BMI which had previously made a fortune off the British band known as the Beatles.
Up until the middle of the 20th century in the United States, childbirth was considered to be the most feared part of a woman's life.
"Go into any old graveyard, and you always see a number of women who died in their 20s," Baker said. "That was in a large part due to childbirth."
With the advent of techniques in anesthesia, cesarean section, and forceps delivery, the chances of a successful have pregnancy improved, at least in developed countries. Unfortunately, many resource-poor societies around the world still lag behind in this arena.
Few surgical interventions today carry as much complexity -- or as much ethical significance -- as organ transplantation.
"It's such a technically complex intervention that it's an amazing thing that it can even be done," Baker said. "It ties together both surgery and immunology."
The first successful transplant operation, which took place in 1954, removed a kidney from one donor and installed it in the body of his identical twin. Other organ transplants followed, including the first liver transplant in 1967 and the first heart transplant in 1968.
Today, there are more than 90,000 people awaiting a transplant in the United States alone -- a situation that also reveals the moral considerations that come entwined with such techniques.
"It represented an important turning point in the field of medical ethics," Baker said. "It really challenged physicians' ethic of 'first, do no harm.'"
Considering the progress that has been made in years past, it is tempting to view the state of health and medicine today as an endpoint.
"Medicine has made it possible to deal with many conditions," Baker said. "Our lives are longer. Still, we have to say in all honesty that our control over chronic diseases is somewhat mixed."
Additional research into how best to stave off these conditions -- even by delving into the secrets of the human genome -- could represent the next hopeful steps toward healthier, longer lives.
"In the future, I think we will begin to see more and more applications from genomic medicine, which will help us identify individuals at risk for chronic diseases and allow us to intervene earlier," Baker said.