Bloating, fatigue and brain fog almost always turn out to be something ordinary. Here's how to tell the difference — and what actually finds a parasite when there really is one.
Could it be a parasite? The field guide
They're far more often IBS, diet, stress, or thyroid. The overlap is complete enough that no symptom list can separate them — which is exactly why this site exists.
Compare your symptoms →The females crawl out to the skin after dark, which is the entire reason the itch peaks then. It's the most common worm infection in the United States — and a short course of medicine clears it.
The six worth knowing →The larvae burrow straight through skin touching contaminated soil — no swallowing required. Which is why shoes do most of the prevention work abroad.
Water, food, and skin →Routine ova-and-parasite testing finds Giardia 66–79% of the time, and Cryptosporidium less than 5% of the time without a special stain. If you're going to test, which panel you pick matters more than most people realise. What to ask for →
CDC states that chlorine bleach and iodine kill bacteria and viruses but do not work well to kill parasites. Boiling does. So does a filter rated for cyst removal. The tablets in most travel kits don't. Water, food and skin →
The tape test is the standard, but eggs aren't laid every night. CDC advises three consecutive mornings, prior to bathing — one report found that takes sensitivity from 50% to 90%. The night-time itch →
Four pages, plain English, CDC and WHO sources. What your symptom usually means instead, the red flags worth a doctor, and a printable prevention checklist.
Prefer to read something right now? See the prevention checklist →