Parasitic worms, commonly known as helminths, are large organisms that can often be seen without a microscope. These parasites typically live inside the human body, especially in the intestines, where they are transmitted through contaminated soil or food. Some types, such as schistosomes, live in blood vessels rather than the digestive system. While certain worm-like parasites exist on the outside of the body, true helminths are those that live internally and depend on a host to survive.
These parasites feed on their host while weakening the body’s ability to absorb essential nutrients, which can lead to fatigue, illness, and long-term health problems. They are a major global health concern, particularly in areas with limited sanitation. Parasitic worms have complex life cycles that require stages both inside and outside the human body, and they can survive for years by evading the immune system. Their eggs are highly durable, allowing them to persist in harsh environments and spread infection easily.