Updated on September 11, 2025.
Maybe you've heard of tapeworms. These parasitic flat worms can live in human intestines for years—often so quietly, a person doesn't know they're infected.
Here's what to know about tapeworms, including signs to watch for, treatments, and how to avoid them in the first place.
What are tapeworms?
Ribbon-shaped tapeworms have a sucker on one end and range in size from about 1 inch to 10 yards or more. Their bodies are divided into smaller segments, which can break off and release eggs. A person becomes infected by swallowing eggs or larvae.
Tapeworms feed off the nutrients in the gut. More than 9,000 different species of the worms are recorded, but only a few cause trouble for humans. Infections are not common in the United States.
What symptoms can tapeworm infections cause?
Tapeworm infections don't usually cause symptoms. If they do occur, they may include:
- Abdominal pain
- Fatigue
- Loss of appetite
- Upset stomach
- Diarrhea
- Weight loss
Some people develop nutritional deficiencies. Young children with bad infections may have headaches, an itchy bottom, and trouble sleeping.
There’s one big exception: If people swallow the eggs of certain tapeworms, the worms can invade other parts of the body and form cysts in muscles, the brain, or other organs. This serious disease, called cysticercosis, can lead to muscle or eye damage, headaches, seizures, or even strokes.
What are tapeworm signs to look for?
If you think you have a tapeworm infection, check your stool. You may be able to see tapeworm segments that you’ve passed.
How are tapeworm infections prevented?
Eating undercooked or raw beef, pork, or fish can cause tapeworm infections. You can also get tapeworms by consuming food or water contaminated with feces from a person or animal that is infected.
To avoid infection, make sure you and all the members of your family wash your hands properly, especially before making food and after using the bathroom or changing diapers. Also, ensure that all meat is cooked properly and double-check it with a food thermometer.
How are tapeworm infections treated?
See a healthcare provider (HCP) if you think you’re infected. You may need stool tests, an X-ray, or other tests. If you are indeed infected, your HCP will likely prescribe a medication called praziquantel to treat it.
Can an infected dog or cat spread the infection?
Yes, but it’s unlikely. Pets normally become infected by swallowing a flea carrying a tapeworm. A person would also have to swallow an infected flea to get the worms, and this is incredibly rare.
