What Are the Effects of Tapeworms in Humans?

Tapeworms enter the human body through consumption of contaminated food or improper food handling. The most common type of tapeworms are found in beef (Taenia saginata) and pork (Taenia solium). The medical term for tapeworm infection is Taeniasis. Tapeworms enter the body as larvae and can grow into adult tapeworms; adult tapeworms can grow as long as 12 ft. Prognosis is generally good, with complications rare. According to MedlinePlus, tapeworm infection is rare in the U.S. and more common in developing countries.

Is This an Emergency?

If you are experiencing serious medical symptoms, seek emergency treatment immediately.


Generally, there are no visible, bodily symptoms of a tapeworm infestation. Often, the only sign a tapeworm infestation is present is the visual site of a tapeworm segment, often moving, in a bowel movement. However, some patients may experience nausea, weakness, decreased appetite or diarrhea.

Central Nervous System Disorders

Pork tapeworm larvae that move out of the intestines and into the brain may cause neurocysticercosis. Cysts form throughout the brain and spinal cord. The cysts in the brain cause seizures or symptoms similar to brain tumors. Spinal cysts result in general weakness and overall difficulty walking. More severe complications, such as meningitis, hydrocephalus or dementia, can occur. In rare cases, death may result.

Organ Function Complications

Invasive parasites moving out of the intestinal and abdominal area may affect specific organs in the body. Worms in the heart can cause heart arrhythmias or, even, heart failure. Eye lesions result in vision loss or blindness. Cysts can grow throughout the body, causing increased pressure on nearby blood vessels and block circulation. The blood vessels may rupture. Emergency surgery or organ transplant is necessary in the most severe cases.


Generally, there are no complications with a tapeworm infestation. If the worms grow too large, they may cause blockage. Blockage is commonly seen in the intestines, bile duct, appendix or pancreatic duct.