Drug resistance occurs when microorganisms, such as bacteria or viruses, evolve and become less susceptible to the effects of medications designed to kill or inhibit them. This can happen through genetic mutations or the acquisition of resistance genes from other organisms. As a result, standard treatments become less effective, making infections harder to treat. One common example of drug resistance is seen in antibiotic-resistant bacteria, which can lead to longer hospital stays and increased healthcare costs. The overuse and misuse of antibiotics in humans and animals contribute significantly to this problem, highlighting the need for responsible medication practices.