Snakes need a clean, dry, warm, roomy cage, with a fresh water supply. Avoid bark bedding, corncob bedding and walnut bedding. Most snakes do well if kept at 80F to 90F, but check with your veterinarian for individual species requirements. It is optional to provide UVA/UVB light, but it is often done to promote serotonin production and contentment. Snakes need to see the vet 1-2 times per year for an examination and a fecal check. Other diagnostics may be needed.
Bite wounds from live prey (need to teach snake to eat killed food), mouth rot often associated with upper and lower respiratory infection or pneumonia, and parasites. Medical problems are usually associated with a poor environment such as a cold, dirty cage. Some snakes get blister belly or inflamed swollen scutes from a heat source that is too hot. Many snakes have mite, ticks, or internal parasites.
Remember to always wash your hands after handling any animal, especially reptiles and amphibians. See information from the CDC about reptiles and contagious salmonella infections.