From unexplained weight gain to migraine headaches, parasites may be the missing piece to your symptom puzzle.

In any medical training, the first thing students are taught is to recognize what’s common and what’s dangerous. Unfortunately, even though parasites can fit in both of these categories, they are often not covered in traditional medical education. So, unless your health care provider has done additional training in parasitology or even tropical diseases, your parasite symptoms may go unnoticed, leaving you with confusing diagnoses that don’t provide any real answers.

In more than 4 decades of working with clients, I’ve lost count of how many improved dramatically after finding and treating their parasite problem. It’s a far more common issue than you’d think – more than 1.2 million people in the US contract giardia from contaminated water each year, and more than 40 million adults and children in the US carry the toxoplasma parasite – and this is only 2 of the hundreds of parasites that have been recorded by the CDC as being in the US.

If you think you might have a parasite, take the Parasite Quiz here.

What starts out feeling like food poisoning may actually be a food-borne parasite, and once a parasite takes hold in your gut it can travel anywhere and wreak havoc on susceptible tissues and organs. Or you could swim in contaminated waters and come out with an unexplained rash you just can’t seem to clear. Regardless of the exposure, health care providers aren’t quick to jump to parasites as the possible cause. So I’ve compiled this list of common symptoms of parasites that your doctor may miss.

Gastrointestinal Complaints

• Gas and Bloating

Some parasites live in the upper small intestine, where the inflammation they produce causes both gas and bloating. You may even be diagnosed with SIBO as a result, but not respond well to the antibiotics. This situation can be magnified when you eat difficult to digest foods like beans or raw fruits and veggies. Persistent abdominal distension is a frequent sign of hidden hitchhikers and can persist intermittently for many months or years if the parasites aren’t eliminated from the body.

• Constipation

Some parasites cause inflammation that slows the transit time of the bowels. Some worms, because of their large size and shape, can physically obstruct some organs. Heavy worm infestations can block the common bile duct and intestinal tract, making elimination infrequent and difficult.

• Diarrhea

Certain parasites, primarily protozoa, which are microscopic, produce a hormone-like prostaglandin that creates an electrolyte imbalance that leads to frequent, watery stools. The diarrhea process in parasite infection is then a function of the parasite, not the body’s attempt to rid itself of the infectious organism.

• Irritable Bowel Syndrome (IBS)

Parasites can irritate, inflame, and coat the intestinal cell walls, leading to a variety of gastrointestinal symptoms and malabsorption of vital nutrients, especially fats. This malabsorption and irritation leads to bulky stools, fatty stools, and unpredictable bowel patterns.

Nervous System Disturbances

• Sleep Disruptions

Multiple awakenings through the night, particularly between 2am and 3am, are possibly caused by the body’s attempts to eliminate toxic wastes from parasites via the liver. According to Traditional Chinese Medicine (TCM), these hours are governed by the liver. Sleep disturbances are also caused by the nocturnal habits of some parasites, that cause more central nervous system irritation at night with their increased movement. Or, in the case of pinworms, work their way out to the anus to lay eggs and cause intense itching and discomfort.

• Chronic Fatigue

Chronic fatigue syndrome symptoms include fatigue not relieved by rest, flu-like symptoms, apathy, depression, impaired concentration, and memory issues. Parasites cause these physical, mental, and emotional symptoms through malnutrition resulting from malabsorption of proteins, carbohydrates, fats, and especially vitamins A and B12.

• Bruxism

The grinding, clenching, and gnashing of the teeth has long been considered a hallmark sign of parasitic infection. These symptoms are most noticeable among sleeping children, though dentists pick up on signs when they are examining your bite pattern. Bruxism may be a nervous system response to the internal foreign irritant, though the medical literature isn’t clear on the actual etiology.

• Nervousness

Parasitic metabolic wastes and toxic substances can serve as irritants to the central nervous system. Restlessness and anxiety are often the result of systemic parasite infection.

Skin Signs

• Cysts and Granulomas

These tumor-like masses encase destroyed larva, parasite eggs, or a secondary infection that the body has walled off. They develop externally on the skin, but can also manifest internally in the colon and rectal walls, lungs, liver, peritoneum, and uterus.

• Allergic-Type Skin Conditions

Intestinal worms can cause hives, rashes, weeping eczema, and other unexplained allergic-type skin reactions. Cutaneous ulcers, swellings, and sores, papular lesions, and itchy dermatitis can all result from microscopic protozoan invasion.

• Immune Dysfunction

Parasites suppress immune system functioning by decreasing the secretion of immunoglobulin A (IgA). Their presence continually stimulates the immune system response and over time can exhaust this vital defense system, leaving the body open to bacterial and viral secondary infections.

• Joint and Muscle Pains

Parasites are known to migrate and encyst in joint fluids, and worms can encyst in muscles. One this happens, pain becomes evident and is often assumed to be caused by arthritis. Joint and muscle pains and inflammation are also the result of tissue damage caused by some parasites or the body’s ongoing immune response to their presence.

• Anemia

Some varieties of worms attach themselves to the mucosal lining of the intestines and leach nutrients from the body. If they are present in large enough numbers, they can create enough blood loss to cause either iron deficiency or pernicious anemia.

What to Do When You Suspect a Parasite

My classic book, Guess What Came to Dinner?, is considered by many natural health practitioners to be the premier parasite primer, and I highly recommend getting a copy pronto if you suspect you have a parasite. You’ll learn everything from the most common parasitic infections in the US and their associated symptoms, to available options for testing, treatment and cleansing. This book was also the inspiration for the formulation of UNI KEY Health’s My Colon Cleansing Kit, which contains everything you need for a gentle yet thorough – and highly effective – cleansing of the colon, the main entry point for parasites into your body. I have personally used this formula with even my most sensitive clients for decades, with overwhelmingly positive results.