Worm infestations create symptoms such as lethargy, abdominal cramping, disturbed bowel habits, rectal itching and weight loss, according to DoctorOz.com. Worms can cause a range of health complications according to their species and location in a person's body.
People generally catch worms through exposure to unsanitary conditions and undercooked meats, explains DoctorOz.com. For example, Dientamoeba gragilis is likely spread through feces and causes diarrhea and dark, sticky stools after it implants itself in the intestines.
Hookworms can enter the body through the skin and are commonly contracted by walking barefoot outdoors. They can be caught and treated early if people know how to recognize the rash they often produce at the site of penetration, says DoctorOz.com.
Pinworms are common among children and are easily spread through contact with contaminated toys, bed linens and hands. DoctorOz.com explains that these worms enter the body through the mouth and eventually make their way to the anus, where they cause extreme itching, especially during the night.
Some worms, such as tapeworms, can live in the intestines for an extended period of time without producing many noticeable symptoms, according to WebMD. There are several species of tapeworm, all of which are contracted by eating undercooked meat. Tapeworm eggs exit the digestive system through the stool and can spread between people who do not wash their hands thoroughly after using the bathroom.