Disease was responsible for the deaths of more Union soldiers than were the Confederates. Nearly 60% of the Federal deaths in the war were the result of disease. About half of those deaths were the result of internal disorders, primarily dysentery, diarrhea and typhoid fever. The other half died of mostly tuberculosis or pneumonia. Virtually all of the Union soldiers had chronic diarrhea or dysentery at one point or another. Malaria epidemics swept through the armies striking more than one million men in the Union Army alone. Living conditions were often extreme, cleanliness virtually non-existent, and germs spread and mutated with alarming intensity. Simple colds frequently turned into pneumonia. Doctors were often powerless to save the life of a man attacked from within by the organisms of disease. They generally had little more success repairing the bodily damage caused by the invasive insult of a bullet or shrapnel.
The average medical student of the time had most likely received only two years of training at best. There was very little clinical or laboratory experience. Most medicines were carried in pill form. Soluble tablets were unknown. Opium was used instead of morphine, there were no heart stimulants, and penicillin wouldn't come into use for another seventy years. Venereal disease, which afflicted an estimated 8% of all Union soldiers, was typically treated with pokeweed, elderberries and mercury to relieve the symptoms, though it offered no cure. Wounds inflicted by the infamous minnié ball created an enormous impact wound. A hit to an arm or leg would nearly always shatter the bone. Surgeons sometimes treated flesh wounds by amputating the wounded limb. It was faster, they said, and often easier than the appropriate treatment. There was a 17% chance that amputation would result from an extremity wound. Then, if the patient survived the surgery, there was an exceptionally high risk of infection.
After physical damage, the most prevalent casualty of war is the emotional well-being of the combatants. The medical validity of conditions later identified as "battle fatigue," or "post-traumatic stress disorders" were unknown at the time of the Civil War. Physical exhaustion, sleep deprivation and the emotional trauma of combat rendered many strong men nearly helpless. Treatment for the psychological damage of war was non-existent. It was acknowledged of course, that some soldiers occasionally "went crazy," and no further explanation was necessary to those who had themselves battled the inner demons resulting from the vast horrors of war. As inadequate as were the capabilities of the medical corps to deal with these psychological wounds, the families left behind were even more unprepared. The sons, husbands and fathers that returned to them after the war were sometimes unrecognizable as the peaceful and gentle men they had once known.