Parasitic infections: what to watch for and how to act

Parasitic infections can feel scary, but most are diagnosable and treatable. If you have sudden stomach pain, persistent diarrhea, unexplained weight loss, itchy skin or odd fatigue after travel or risky food, parasites could be the cause. This page gives clear, practical steps you can take right now: spot common signs, get tested, and handle treatment safely.

Common parasites & symptoms

Worms like pinworms, roundworms, and tapeworms often hit the gut. Symptoms include stomach cramps, diarrhea, visible worms in stool, or itchy bottom (pinworms show worse at night). Protozoa such as Giardia and Entamoeba cause watery diarrhea and bloating after contaminated water or food. Blood parasites (like malaria) and skin parasites (scabies) have different patterns—fever and chills for malaria, a very itchy rash for scabies.

Timing helps: if symptoms start after travel, camping, or eating unwashed produce, tell your provider. Kids and people with weak immune systems show stronger signs and may need faster care.

Treatment, tests, and staying safe

Testing is usually a stool sample, blood test, or skin scraping—simple and fast. Treatment depends on the bug: metronidazole (Flagyl) treats some protozoa, albendazole and mebendazole treat many worms, and ivermectin treats certain parasites and scabies. If you’re worried about Flagyl side effects or shortages, our piece “10 Flagyl Alternatives in 2025” lists options and when they might apply. Always check with a clinician before swapping meds.

Thinking of buying medicine online? Be careful. Our guides on buying antibiotics and other drugs online explain how to spot legit pharmacies and avoid fakes. Never start prescription antiparasitic drugs without a proper diagnosis and advice from a healthcare pro.

Preventing infection is often easier than treating it. Wash hands well, drink treated water when traveling, cook meat to safe temperatures, wash produce, and avoid walking barefoot in areas where parasites spread through soil. For pets, keep up with vet-recommended deworming—animal parasites can jump to people.

When to see a doctor? Seek care if diarrhea lasts more than two days, you have a high fever, blood in stool, severe abdominal pain, or signs of dehydration. For kids, infants, pregnant people, or anyone with weakened immunity, contact a provider sooner.

On this tag page you’ll find practical articles about treatment options, safe online pharmacies, and alternatives when common drugs are unavailable. Use those resources to learn more, but treat a medical visit as the priority. Quick testing and the right drug usually clear most parasitic infections fast—so act early and stay safe.