PFAS GUIDE · HEALTH
PFAS Health Effects
Last updated: September 6, 2026
Research has tied some PFAS to kidney cancer, testicular cancer, thyroid disease, high cholesterol, a weaker immune response, ulcerative colitis and problems in pregnancy. Those are patterns found across large groups. They do not prove that PFAS caused any one person’s condition, and what matters is which chemical, how much of it, and over how long.
For the broader background, start with What Are PFAS (Forever Chemicals)? and Are PFAS Dangerous to Humans?
This page provides general educational information only and does not constitute medical or legal advice. Discuss any health concern with a qualified medical professional.
- Major reviews tie certain PFAS to specific cancers, thyroid disease, cholesterol, immune effects, ulcerative colitis and pregnancy problems.
- These are patterns across populations, not findings about individuals.
- Two chemicals, PFOA and PFOS, account for most of the evidence.
- Risk tracks which chemical, how much, and how long.
- Whether to get tested is a decision to make with a doctor.
Where the Evidence Comes From
Three bodies of work carry most of the weight.
The C8 Science Panel studied tens of thousands of people in the Ohio River Valley whose drinking water carried PFOA. US federal health agencies have published their own assessments. And in 2022 the National Academies reviewed the field and issued guidance for doctors.
All of them look at patterns across large groups, because nobody can ethically dose people with a chemical to see what happens.
Conditions Associated With PFAS
The ones that come up most often:
- Kidney cancer — one of the most consistent findings, especially with PFOA.
- Testicular cancer — also reported in heavily exposed groups.
- Thyroid disease — including shifts in thyroid hormone levels.
- Ulcerative colitis — a bowel condition the C8 panel connected to exposure.
- High cholesterol — one of the most commonly seen effects.
- Liver enzyme changes — markers that can point to effects on the liver.
- A weaker immune response — including less antibody response to some vaccines.
- Pregnancy problems — high blood pressure in pregnancy and lower birth weight.
These are also the injuries that come up most in the lawsuits. See PFAS Water Contamination Lawsuits.
Why "Associated With" Is Not "Caused By"
A link means a condition shows up more often in a more exposed group. It does not show that the exposure produced one person’s illness.
Lots of things influence whether someone gets sick, and a study describes risk across a group rather than predicting what happens to you. In a courtroom the same gap is the hard part: connecting one diagnosis to one exposure turns on which chemical, what the exposure was, when it happened, and what the medical records show.
Dose, Duration, and Which PFAS
How much and how long usually decide risk. PFAS complicate that because they build up instead of clearing out, so years of small amounts is the pattern under most scrutiny.
Which chemical matters too. There are thousands of PFAS, and nearly all the strong evidence involves two older ones, PFOA and PFOS. The rest are far less studied. See PFAS vs. PFOA vs. PFOS Explained and How Long Do PFAS Stay in the Body?
PFAS Blood Testing
A blood test can measure how much PFAS is in you. What it cannot do is tell you whether you will get sick.
Clinical guidance suggests testing may be worth it for people with likely heavy exposure, alongside a conversation about screening. Whether it helps in your case is a decision for a clinician, not a web page.
Trying to understand whether you were exposed in the first place? The free PFAS exposure checker on Lawsuit Center sorts drinking water, firefighting foam, occupational, and farm/biosolids paths in four short questions. No contact info required to see your result.
Try the Free PFAS Exposure CheckerWhat People Often Do Next
Usually three things. Talk to a doctor about their exposure history and anything they have noticed. Find out whether their water supply has been tested. And cut down ongoing exposure where they can.
Anyone looking at the legal side runs into filing deadlines, which differ by state. See PFAS Lawsuit Statute of Limitations by State.
Common Questions
Does PFAS cause cancer?
Research ties certain PFAS, mainly PFOA and PFOS, to kidney and testicular cancer. That is a pattern across populations, not proof about any one person’s cancer. Learn more →
What level of PFAS exposure is harmful?
There is no single agreed line across all PFAS and all conditions. It depends on the chemical, the amount, and the years.
Should I get a PFAS blood test?
It measures levels. It does not predict outcomes. Whether it is worth doing is a question for a clinician.
