Let’s be honest: It’s not easy to read a regular old two-lined pregnancy test. Is that a faint line? Is it a positive? Is it a negative? And what’s the deal with evaporation lines? Taking pregnancy tests can seem stressful with all the what-ifs, but we’ve got the answers to help make the process a little bit easier for you.

In this post, we’ll answer your questions about evaporation lines, including:

  • What is an evaporation line?
  • What do evaporation lines look like?
  • What’s the difference between an evaporation line and a faint positive?

What is an Evaporation Line?

An evaporation line is a line that appears on the test once the urine has dried—or evaporated.

Pregnancy tests are meant to be read when they are wet. This is why pregnancy tests give specific directions. For instance, a test might say “Dip the pregnancy into a cup of urine for five seconds, then read the results in two minutes. Discard the test after 10 minutes.”

Once the time allotted for the pregnancy test expires, and the urine starts to dry, it can leaven an evaporation line. The faint mark this leaves behind resembles a faint line on a pregnancy test.

That’s why it’s so important to follow instructions on pregnancy tests. All tests do not share the same directions, so always read the directions—especially if you switch between brands and styles of tests.

What Do Evaporation Lines Look Like?

What does an evaporation line look like?

(image source)

Evaporation lines are generally more muted than the control line.

  • On a pink dye test, an evaporation line may look like faded gray.
  • On a blue dye test, the line can appear as gray or even a lighter shade of blue. (Note: For some reason, anecdotally, many mamas find that blue dye tests are more prone to evaporation lines.)
  • Sometimes, though, the evaporation line appears as a colorless streak, almost like an indentation.

An evaporation line is also often thinner than the control line. In the image above, you can see that the horizontal line is one thickness, while the vertical evaporation line is much thinner and of uneven thickness.

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Evaporation Lines vs. Faint Positive Lines

If you’re unsure if your pregnancy test is depicting an evaporation line or a faint positive, it can be frustrating. Luckily, there are a few tips for differentiating between the two.

Evaporation Lines vs Faint Positive Lines Chart – hat Does an Evaporation Line on a Pregnancy Test Mean pregnancy post by Mama Natural

What to Do If You’re Still Not Sure…

If you take a pregnancy test and are not quite sure what your result is, it’s a good idea to continue taking tests. Always try to use FMU (first morning urine), as this urine is the most concentrated with hCG, the pregnancy hormone that your test is trying to detect.

  • If you had a true evaporation line, future tests will show a negative result.
  • On the other hand, if your test showed a faint line, you should continue to see the line darkening with each day that progresses. (See image below.) An evaporation line will not do this.
Is Your Positive Pregnancy Test For Real Find Out Now – Mama Natural – Genevieve

What Else Can Cause a Faint Line?

Here’s a bit of good news: Not all faint lines are evaporation lines.

If you think you’re pregnant

If you’re certain that you followed the instructions (and read the test within the recommended time frame), and you continue to see what you think is a faint line, you are probably pregnant. The pregnancy test is detecting minuscule levels of hCG, a hormone that rapidly increases when pregnant. Many pregnancy tests can detect as little as 25 mlU/ml hCG! (source)

A quick trip to your midwife or OBGYN can confirm your pregnancy with a blood hCG test. A urine test simply says “Yes, there is hCG” or “No, there is not hCG.” A blood hCG test, however, will also reveal how much hCG is present—a stat which also helps determine how far along you are.

Or, you can simply wait a day or two and retake a pregnancy test. (In fact, some midwife and doctor offices will have you re-test yourself with a home pregnancy test once you miss your period because they are very accurate.) If the faint line appears darker, this is confirmation that you are most likely pregnant.

If you don’t think you’re pregnant

In rare cases, a faint line can indicate a false positive and you might not actually be pregnant. In these cases, a faint line could possibly be attributed to the following conditions:

  • Hormonal imbalances: Hormones trigger the positive result on a pregnancy test, and sometimes hormonal imbalances from conditions like PCOS can trigger a false positive. (source)
  • Fertility medication: If you’re struggling to conceive, your healthcare provider may have suggested various fertility medications. Some medications can also cause a false pregnancy test result.
  • Menopause: Interestingly, perimenopause (the months preceding official menopause) can affect your hormone levels. The symptoms of perimenopause and menopause can sometimes mimic the symptoms of pregnancy, so it’s understandable if you’re confused which life phase you’re entering. Fluctuating hormones can even cause a spike in false positives. (source)
  • Illness: Some medications used for conditions like epilepsy or Parkinson’s Disease can trigger a false positive result on a pregnancy test.
  • hCG diets and supplements: The hCG diet is a very low calorie diet that is supplemented with hCG. Typically, this is a type of medically-supervised weight loss program used when individuals have extreme weight loss needs. Since pregnancy tests detect hCG, this could result in a false positive.

What About You?

Have you ever had an evaporation line show up on a pregnancy test? Share your experience below!