Tapeworms vs. Pinworms: Which Is More Dangerous?

Medically Reviewed by Zilpah Sheikh, MD on May 14, 2024
8 min read

Pinworms are also called “threadworms.” They’re the most common type of intestinal worm infection in the U.S. and one of the most common in the world. They’re thin and white and about one-quarter to one-half inch long -- about as long as a staple.

Tapeworms are flatworms that look a bit like ribbons. Their bodies are made up of segments, and each segment is about the size of a grain of rice. Adult tapeworms can grow to be 30 feet -- almost as long as the average school bus.

How common are pinworm and tapeworm infections in humans?

In the U.S., about half of kids between the ages of 5 and 10 will have a pinworm infection at some point. 

Tapeworm infections in the U.S. are rare. Experts estimate there are about 1,000 new infections each year, but reliable numbers are hard to come by. It's more common in places where cattle and humans live closely together and people don't have access to good sanitation, such as areas near feedlots. It's common in places where people eat raw beef that's infected, such as Russia, Eastern Europe, Eastern Asia, and Latin America. It's also more common where people eat undercooked pork that's infected. Infection rates are higher in Latin America, Eastern Europe, sub-Saharan Africa, India, and Asia. In the U.S., it's more likely to affect immigrants from Latin America.

There's also a version of tapeworm that's specific to Asia. Those infections happen mostly in the Republic of Korea, China, Taiwan, Indonesia, and Thailand.

Pinworms are spread from feces to the mouth. It can happen directly, like when your dirty fingers touch your mouth or food. It can also happen indirectly, like when you touch an object that’s contaminated with eggs. Tiny pinworm eggs can live on surfaces -- toys, bathroom fixtures, school desks, or bed linens -- for up to 3 weeks.

Once inside your body, pinworms make a home in your colon and rectum. At night, female worms come outside to lay eggs in the skin around your anus. If you scratch the area, the eggs get on your fingers or under your nails, and then spread to the next thing you touch. This is why pinworms are spread so easily among young children.

Tapeworms can live outside for months, waiting for a host to come along. You’re most at risk if you work around livestock or travel to a country that lacks clean drinking water and modern sewage systems. You can be infected if you eat or drink something that contains tapeworm eggs or larvae, such as raw or undercooked beef, pork, or fish. You also can be exposed to tapeworms through contaminated water.

Once inside your body, the tapeworm head attaches to the wall of your intestines. It uses the food you eat to grow new segments. The older segments, which contain eggs, then break off and leave your body with your poop.

You may not have any symptoms at all from these parasitic infections.

Pinworm symptoms

You might have anal itching, especially at night. You could also have stomach pain, nausea, or vaginal itching. Sometimes, pinworms can be seen around your anus or on your underwear or bed sheets about 2-3 hours after you’ve gone to bed.

Pinworms can cause insomnia, restlessness, and irritability.

Most of the time, pinworms don’t cause major problems. But in rare cases, they can cause infections of the vagina and uterus.

Tapeworm symptoms

You might have nausea, stomach pain, weakness, or diarrhea. You might notice a change in appetite (eating more or less than usual). And since the tapeworm keeps your body from absorbing nutrients from food, you may lose weight. You might crave salty foods.

If you get tapeworm from eating pork (it’s actually called the pork tapeworm), the eggs enter your bloodstream and hatch in your tissues. There, they form fluid-filled cysts, which doctors call “cysticercosis.” This can cause a wide range of possible symptoms, depending on where the cysts develop and how much inflammation they cause. Some of these may include vision changes, lumps on the skin, neurologic changes, or seizures.

If your doctor suspects you have pinworms, you may have to do a “tape test.” As soon as you wake up in the morning, you’ll place a piece of clear tape around your anus, then gently peel it off. Any pinworm eggs will stick to the tape, which your doctor can see under a microscope in a lab.

A tapeworm infection is usually diagnosed by finding eggs or tapeworm segments in the stool. Your doctor may ask you to bring in a sample so a lab can look for eggs, larvae, or tapeworm segments. A blood test can spot antigens, foreign substances that let your doctor know your body is trying to fight the infection. Sometimes, an MRI or CT scan can find cysts formed by the pork tapeworm.

Some over-the-counter medicines (pyrantel pamoate) kill pinworms. Your doctor also could prescribe an antiparasitic medicine. Common prescription medicines for pinworm are mebendazole and albendazole (Albenza). Everyone in your family should be treated — even if they don’t have symptoms. Two doses are often needed to ensure the infection is gone for good. The drugs can cause digestive side effects.

Sometimes, you don’t need to do anything about a tapeworm. It could leave your body on its own. But if your doctor finds it, they can prescribe an antiparasitic medicine. Those include:

  • Albendazole
  • Nitazoxanide (Alinia)
  • Praziquantel (Biltricide)

The medicine will either kill the adult worms or cause you to poop them out. But they won’t kill the eggs, which can still cause infections. You’ll probably need to give your doctor a stool sample for a few months to make sure all the tapeworms are gone.

It’s harder to treat an infection caused by tapeworm cysts. In addition to the medicine that kills the tapeworm, you may need other medicines, such as:

  • Corticosteroids to reduce swelling and other immune system activity that may damage organs, muscles, or other tissues
  • Antiepileptic medicine to help prevent or stop seizures caused by larval cysts in the brain

You also might need a procedure to deal with cysts. Those can include:

Surgery. A surgeon removes a larval cyst.

Alternate procedure. A specialist uses a fine needle to remove some fluid from the cyst. They inject a treatment into the cyst to kill it. Then, they remove all of the fluid in the cyst. This is done when surgery isn't possible.

Shunt. A tube, called a shunt, is inserted to drain excess fluid in the brain.

Some key steps to avoiding tapeworm and pinworm infections are the same — wash your hands with soap and water before eating or handling food, and after you use the bathroom or change a diaper.

Steps you can take to prevent pinworm infections include:

  • Keep your fingernails clipped short.
  • Take a shower or bath every day (in the morning is best, because pinworms lay eggs at night).
  • Try not to scratch around your anus or between your legs.
  • Change your bed linens and underwear every day.
  • Wash your clothes, bed linens, towels, and washcloths often in hot water.

To help prevent tapeworms, try these things:

  • Don’t eat raw or undercooked beef, pork, or fish. You can use a meat thermometer to check doneness.
  • Rinse your fruits and vegetables before eating them.
  • Wash cutting boards and kitchen utensils that come into contact with raw meat or unwashed fruits or vegetables.
  • Freeze your meat and fish. Keeping it frozen for 7 days before you prepare it can kill tapeworms.
  • If you have a pet with tapeworm, treat it right away. Generally, cats and dogs get a type of tapeworm that infests fleas. But it's still wise to get rid of any tapeworm from your home.

If you're traveling to a place where sanitation is not advanced, keep these additional precautions in mind:

  • Only drink water that is bottled or that has been boiled for 1 minute.
  • Canned or bottled carbonated drinks are safer than untreated water.
  • You can filter water yourself. Absolute 1-micron filters are available at camping supply stores. You should dissolve iodine tablets in the water.

Tapeworms and pinworms are parasites that can get into your digestive system. Pinworms are the most common parasitic infection in the U.S. and often affect young children. Tapeworm infections in the U.S. are less common. If you're infected with either parasite, you may not have many symptoms. Pinworms often cause itching around the anus. Tapeworms can cause digestive problems. Both can be treated with drugs to kill the parasites. You can avoid pinworms and tapeworms by washing your hands often — before you eat or prepare food, and after using the bathroom or changing a diaper. If you're traveling to an area that lacks good sanitation and where tapeworm is common, be wary of drinking water.

What kills pinworms and tapeworms?

Once they're inside your body, you'll need an antiparasitic drug to kill tapeworms and pinworms. Washing your hands can keep them from infecting you. Washing bed linens and clothing can help prevent pinworms. Washing fruits, vegetables, and kitchen utensils can prevent tapeworms. 

How do you know if you have a tapeworm or other parasites?

You might not have any symptoms at all from a parasitic infection. If you have a tapeworm, you might have digestive problems. You might also feel tapeworm segments leaving your body through your anus. The tapeworm might be visible in your poop.

If you have pinworms, you might have itching around your anus, especially at night. That's when pinworms lay eggs.

What do pinworms look like in stool?

Pinworms are white. They're about a half-inch long and very thin — about the size of a staple.

Are tapeworms always visible in stool?

No, you can't always spot tapeworm segments in your poop. You may not realize you have an infection.

Can tapeworms kill you?

Most cases of tapeworm cause mild illness. However, if you get cysts in your brain, it can cause seizures and other life-threatening complications.