Evaporation Line On A Pregnancy Test

Most of you who have ever taken a pregnancy test and forgot to throw it away must have seen a colorless line in the result window. This line is called an Evaporation Line.

An evaporation line is the mark of urine that remains on the pregnancy test after dried. The nuisance of looking like a faint positive pregnancy test results can confuse you.

A false positive pregnancy test result can be an evap line on a pregnancy test. 

So here is everything discussed in detail about an evap line in a pregnancy test

What is an evaporation line on a pregnancy test?

An evaporation line on a pregnancy test is the  mark left by urine  after it completely evaporates from the hCG strip.

You must read the pregnancy test before the urine dries up. Most pregnancy tests have a very brief time for results to come up. 

What does an evaporation line look like?

An Evaporation Line (also known as an Evap Line) looks like a vertically aligned colorless mark. If it appears very close to the result line, it may be even getting a color.

If you eat anything with food color or beetroots, and saffron it can color urine. The same thing before taking the pregnancy test gives color to the evap lines. 

Eventually, the evap line looks like a faint positive and it is hard to not believe your eyes.

Does an evaporation line have a color? Is an evaporation line positive?

An evap line can have color but never be a positive pregnancy test. It takes longer to appear and may disappear. 

Can evap line appear immediately?

 It is not likely that you see an evap line within few moments after taking the test.

What color are evaporation lines on pregnancy tests?

Fruits like carrots, beetroots, plums, rhubarb, and saffron color your urine. Artificial food coloring additives also give a tinge to urine. Can an evaporation line be pink? Yes, the pink line is because you had a beetroot salad.

Some diseases like Ketouresis color the urine black. So in these cases, the evaporation lines will have color.

What Is An Evaporation Line On A Pregnancy Test?
What Is An Evaporation Line On A Pregnancy Test?

What is the difference between evaporation line and positive pregnancy test?

Evaporation line (Evap Line) looking positive pregnancy test is a human mistake. 

What causes evap lines? 

Mistakes and defects! Either you did not follow the instructions, or the PT couldn’t react. 

The difference between an evaporation line and a positive pregnancy test is:

Evaporation Line vs. Positive Pregnancy Test Result

Evaporation LinePositive Result
Evaporation line is colorlessPositive pregnancy test is colored
Evaporation line comes after result reading time has passed.Positive result comes within result reading time.
Evaporation lines show up in most cases.Positive pregnancy test result will come only if you are pregnant.
Evaporation line is a pregnancy test error.Positive test result is a valid result.

    Is this evaporation line or indent line?

    Indent line vs. Evap line is another thing you must know.

    1. Indent line is the line of hCG detector particles attached to the pregnancy test’s hCG strip.
    2. Indent lines show up if they are intentionally demarcated or when the pregnancy test expires.
    3. An unused pregnancy test may have an indent line, but it can never have an evap line.

    Why does evaporation lines appear in a pregnancy test?

    What causes evaporation lines on pregnancy tests? No medical condition causes evap line. It can be because of fault in PT or handling errors.

    1. Evaporation line does not appear in a quality pregnancy test.
    2. However, if evap lines appear at a later stage while taking a pregnancy test, that is because urine naturally has a pale yellow color.
    3. So once the result reading time is up, the urine dries and shows an evap line.

    In fact, the result reading time of a pregnancy test is dependent on two things:

    • Pregnancy test takes time to estimate hCG hormone level in urine and giving the colored lines.
    • Time for which the urine stays inside the hCG strip of the pregnancy test and doesn’t evaporate completely.

    How to avoid getting evaporation lines?

    It is simple to avoid evap lines and the problems due to them. Keep these things in mind and follow them:

    • Follow the instructions for the particular pregnancy test carefully.
    • Read the results within pregnancy test’s result reading time.
    • Be vigilant of other symptoms of early pregnancy rather than relying on pregnancy test lines.
    • Choose your pregnancy test wisely. Search for the best pregnancy tests and then get the one which has no such problems with it.

      How common are evaporation lines in a pregnancy test?

      1. Brand or Quality of Pregnancy Test: A good quality pregnancy test will have least incidents of occurrence of evaporation lines. However, a low-grade pregnancy test will have evaporation lines appearing frequently.
      2. The timing of Pregnancy Test: If you do not time your pregnancy test accurately then evaporation lines will be common. Taking a pregnancy test too early gives you a false negative result and hoping for a positive you land up with an evaporation line.
      3. Handling of Pregnancy Test: Evaporation lines are all an outcome of delaying the reading of pregnancy test results. Every pregnancy test has a specific result reading time slot. Once you cross this time and evaporation lines will crop up in the result window for sure.

      What is the consequence of getting an evaporation line?

      • The consequences of getting an evaporation line are significant when they make you read a false positive pregnancy test.
      • In case you dismiss a faint positive result as an evaporation line, you’ll be in neck deep trouble.
      • Evaporation lines bring in mental stress and anxiety.

      Is a faint line on a pregnancy test positive?  Evaporation lines and positive result differ mainly in color and time taken to show.

      A big fat positive test result will appear well within the time of the test. Women apprehensive of a false positive, or false negative tend to leave the tests for long. A faint positive PT result is different. It will not take long to appear and will be of proper color.

      Do all pregnancy tests have an evaporation line?

      No. A good pregnancy test does not show an evaporation line at all. They don’t show any change when diluted urine is used. 

      When you perform the test following the instructions evaporation line does not appear. 

      Time is the most significant factor in Positive result vs. evaporation line. 

      Even if you are using a good quality pregnancy test do not cross the reading time. 

      Just like a sheet of paper dipped in water even the hCG strip will shrivel and get a mark.

      Can a faint line on a pregnancy test be wrong?

      A faint or even a dark line can be wrong if the cause is not pregnancy. Some health conditions can cause a false positive result. 

      But do not confuse a faint positive pregnancy test with evaporation line. 

      This is why we tell our readers to not rely on one home pregnancy tests entirely. At least duplicate the home pregnancy test once for assurance.


      1. Wt u writin. I donno what one step pregnancy test evaporation line mean. Tk tst mrng but white line. What is control line. I sorrryyy rude but evap lines are very confusion. Dying 2gt preggo bf leavibg me sv me plz

      2. U rit abt what does evaporation lines look like bt my questn is positive pregnancy test evaporation line, can an evap line be positive? Tell me tis faint positive or evap line. I tk 2 test mah dat due on 31 Jan bt i nly spotn. Dknw wt goin on pz hlp me

        • What is an evaporation line? An evap line a is a faint line or mark of urine. It is not positive even if you see color. You can make out the difference by looking at it. A positive result is clear and neat. It will be a long straight line. Evap line will not be clear straight.

      3. Is faint line different? Exactly, what does evaporation line look like? Please tell me
        difference between evaporation line faint positive like difference between evap and positive pt

        • An evaporation line on pregnancy test is a colorless mark. Just like water crumbles paper after drying a wet paper. A faint positive pregnancy test has color unlike colorless evap line.

      4. Can I get evaporation lines on pregnancy tests just after test? I left test for few second and got a line. It is very thin line and color not visible.

        • Did you look closely. The no color faint pregnancy test line could be having light color. Just after the test evaporation line can occur if urine dried. A colorless line is evap. Take another test if not sure about the faint color of positive test.

      5. Faint positive on pregnancy test is like evap. I missed period for week. My positive pregnancy test or evap line is continuing for the week. I took digital pregnancy test.


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