Disease, poor sanitation, and infection have historically killed far more soldiers in conflicts like the American Civil War and WWI than direct combat, with infections from wounds, dysentery, typhoid, and pneumonia being major culprits due to crowded, unhygienic conditions and limited medical knowledge. In modern times, while disease mortality has dropped significantly, suicide and training accidents now claim more U.S. service members' lives annually than enemy action in recent conflicts.
Abstract. Throughout America's first 145 years of war, far more of the country's military personnel perished from infectious diseases than from enemy action.
The Heaviest Hitters
The number one killer in the world is cardiovascular disease (CVD), including heart disease and stroke, responsible for about one-third of all global deaths, claiming nearly 18-20 million lives annually, and remains the leading cause across all regions, according to WHO and World Heart Federation. While COVID-19 caused significant deaths in recent years, CVD has consistently held the top spot for decades, with increases seen globally, especially in younger populations.
Altogether, two-thirds of the approximately 660,000 deaths of soldiers were caused by uncontrolled infectious diseases, and epidemics played a major role in halting several major campaigns.
An all-encompassing study of the war's casualties reveals that Lee's single losing army incurred about 209,000 casualties (killed, wounded, missing, captured), while General Grant's several winning armies incurred a total of about 154,000 casualties—about 55,000 fewer than Lee's.
Diarrhea and dysentery were the number one killers. (Dysentery is considered diarrhea with blood in the stool.) 57,000 deaths were directly recorded to these most disabling maladies. The total recorded Union cases was 1,528,098.
Hypertension, or high blood pressure, is often called the "silent killer" for good reason.
Heart disease is the leading cause of death for men in the United States, accounting for 25 percent of all male deaths. Various factors, including smoking, high cholesterol levels and obesity, can cause heart disease.
The Five Deadliest Outbreaks and Pandemics in History
Globally, Ischaemic Heart Disease (Coronary Artery Disease) is the number one cause of death, responsible for a significant portion of deaths, with cardiovascular diseases (CVDs) as the leading overall killer, followed by cancer, according to the World Health Organization (WHO). In the United States, heart disease also remains the top killer, while dementia and Alzheimer's are leading causes in places like Australia, with figures varying slightly by country and year.
The 1918 flu claimed an unfathomable 50 to 100 million victims worldwide, including an estimated 675,000 Americans.
Perhaps the most common ailments to strike the camping soldier during the Civil War were bowel disorders. The affliction of both diarrhea and dysentery was so widespread that it came to be called “the runs,” as those suffering from it would often be seen rushing to find a latrine trench.
But the deaths in the World Wars loom even over them: in World War I, more than 7 million soldiers died. And in World War II alone, more than 21 million combatants died.
The number one killer in the world is cardiovascular disease (CVD), including heart disease and stroke, responsible for about one-third of all global deaths, claiming nearly 18-20 million lives annually, and remains the leading cause across all regions, according to WHO and World Heart Federation. While COVID-19 caused significant deaths in recent years, CVD has consistently held the top spot for decades, with increases seen globally, especially in younger populations.
However, we also know that there are ways to reduce your risk of developing 5 of the 6 less survivable cancers.
Studies have suggested that serial killers generally have an average or low-average IQ, although they are often described, and perceived, as possessing IQs in the above-average range. A sample of 202 IQs of serial killers had a median IQ of 89.
Without symptoms, people with high blood pressure may go years without knowing they have the condition until perhaps they've experienced a major health event, thus why it's called the silent killer.
Yes, law enforcement is getting better and better at catching serial killers. “New technology and better training have impacted a killer's ability to move on to more cases,” said Giacalone. “A fast deployment of resources and a relentless follow-up has probably disrupted a number of future cases.
Number of United States military fatalities in major wars 1775-2025. The American Civil War is the conflict with the largest number of American military fatalities in history.
During the American Civil War, disease claimed more lives than bullets, with diarrhea and dysentery responsible for more than 95,000 soldier deaths. Poor sanitation, contaminated water, and overcrowded living conditions turned army camps into breeding grounds for intestinal illness.
TIL The Taiping Rebellion is the bloodiest civil war in world history during which an estimated 20-30M people died. It was started by a guy who thought he was the brother of Jesus Christ sent by the heavens to defeat the Manchus.