Ascaris is a type of parasitic nematode worms known as the "small intestinal roundworms.” These parasites can become quite large, growing up to 35cm! Often, no symptoms are seen with an Ascaris infection. However, in the case of a particularly bad infection, symptoms may include bloody sputum, cough, fever, abdominal discomfort, intestinal ulcer, and passing worms. Ascariasis is also the most common cause of Löffler's syndrome worldwide. Accompanying symptoms include pulmonary infiltration, eosinophilia, and radiographic opacities. Significant increases in infertility are observed in infected women. These worms are seen most often in developing parts of the world. Credit: @themedicalmentors .