What Are the Symptoms of Worm Infestation in Humans?

Worm infestation occurs in humans when parasitic worms, also known as intestinal worms, live and grow inside the body.
Worm infestation occurs in humans when parasitic worms, also known as intestinal worms, live and grow inside the body.

Some of the common symptoms include:

Additionally, each worm infection has the following distinct signs and symptoms:

Types of intestinal worms

Common types of intestinal worms that cause worm infestation in humans include:


Pinworm infestation is the most common roundworm infection. Pinworms are white, tiny, thread-like worms that live in the rectum (the last part of the large bowel). The female worm crawls out of the anus at night and lays eggs in nearby skin causing a terrible itch. Pinworm eggs live up to 2 weeks outside the body on clothing, bedding, toys, toilet seats, or other objects and spread easily.

Roundworm (Ascaris lumbricoides):

Ascariasis is a roundworm infection of the small intestine caused by Ascaris lumbricoides. The worm is usually found in human feces and is transmitted due to poor hygiene from hand to mouth. Adult worms usually grow up to 41 cm long.


Hookworm is a type of roundworm that passed through human feces into the ground. It is transmitted into the host body while walking barefoot on soil infested with hookworm larvae, which pierce through the skin. Hookworms attach themselves to the walls of the small intestine with a hook and live there. They are usually less than half an inch long.

Trichinosis worms (whipworm):

Trichinosis is the third most common roundworm that infects humans. Humans get trichinosis by eating undercooked meat that contains larvae. The larvae mature in the intestines. As they reproduce, the larvae travel outside the intestines into muscle and other tissue.


Tapeworm is a flatworm and looks like a long, white ribbon. These can grow up to 80 feet long and live in a human host for up to 30 years. Tapeworm infection is caused by drinking contaminated water and eating raw or undercooked meat. Tapeworms embed their heads in the intestinal wall and remain there. They produce eggs that mature into larvae that migrate to other parts of the body to form cysts.


Flukes are a type of flatworm that is transmitted to humans through drinking contaminated water as well as eating watercress and other freshwater plants raw. There are many varieties of flukes that live in the intestines, blood, or tissues. These grow up to a few inch in length.


What percentage of the human body is water? See Answer

How is worm infestation in humans diagnosed?

Worm infestation can be diagnosed through studying clinical history, symptoms, and special tests, such as:

  • Fecal test/stool test: Examination of stool samples to find parasites.
  • Colonoscopy: This can be helpful when stool samples do not show evidence of parasites due to diarrhea.
  • Tape test: This test involves touching a tape to the anus several times and then examining the tape under a microscope to identify pinworm eggs.
  • Blood test: To detect some types of parasites in the blood.
  • Antibody test: This test checks for antibodies that the body produces when it is infected with a parasite.
  • Imaging tests: X-rays, computed tomography (CT), or magnetic resonance imaging (MRI) to detect the extent of organ injury caused by worm infestation.

How is worm infestation treated?

Worm infestation can be treated in the following ways:

  • Antiparasitic medication: These kill parasitic worms.
  • Surgery: In very severe cases, surgery is advised when parasites have invaded other parts of the body.
  • Special diet: A customized diet or intake of adequate nutrition may be advised.


Healthy practices of good hygiene can help prevent worm infection:

  • Washing hands with soap before cooking, eating, after playing, changing the diaper, using the toilet, and touching an animal or animal waste.
  • Avoiding eating raw or undercooked meat, fish, or poultry.
  • Washing fruits and vegetables in purified water.
  • Drinking safe clean water.
  • Washing children's toys and clothes with disinfectant.
  • Frequently washing and drying bedding in sun.
  • Avoiding walking barefoot.
  • Cleaning up animal waste and disinfecting the area.
  • Maintaining pet hygiene and deworming pets regularly.

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Bharti B, Bharti S, Khurana S. Worm Infestation: Diagnosis, Treatment and Prevention. Indian J Pediatr. November 2018;85(11):1017-1024. https://pubmed.ncbi.nlm.nih.gov/29127616/

World Health Organization. Intestinal Worms. https://www.who.int/intestinal_worms/more/en/