Evaporation Line on a Pregnancy Test – What it is & How to Avoid

4 min read

Written by Editorial Team

Editorial Team

Evaporation Line On A Pregnancy Test

Most women use the pregnancy test kits at home to first confirm that they are pregnant before visiting the doctor, but do you know everything about the home test? Do you read the instructions carefully before using it? Do you understand how to evaluate the test result? Though you may say “yes” to all the above questions, the answer is actually, “maybe”.

The truth is most of us think we know it all and don’t bother to read the instructions before using the kit. Let’s take a look at why it is important to read and understand how to go about the test.

In This Article

Video of Evaporation Line on Pregnancy Test

How Does a Home Pregnancy Test Work?

Every home pregnancy test kit, irrespective of who the manufacturer is, has a pee stick. It requires that you pee on the stick, the first thing in the morning to ascertain your results. We all know that once we pee on to the stick and within a few minutes if two lines appear, it is positive and if it is a single one, you are unlucky this time too. What we actually do not know is this: the two lines that appear in the pregnancy tests are called: control line and test line.

While the control line appears in every test to let you know that the test is working, the test line appears only when you are pregnant, i.e., if you have sufficient hCG hormone (human chorionic gonadotropin) in your urine which is secreted when you are pregnant and increases as your pregnancy advances. In some cases, the mere appearance of the two lines may not be a confirmation of your pregnancy because the second line may be an evaporation line.

What is an Evaporation Line on a Pregnancy Test?

Evaporation Line on pregnancy kit

Evaporation line, also commonly known as an “evap line” is a line that appears after the test has been taken using the kit and is allowed to sit for a while. To know how much time the stick should be allowed to sit before taking the reading, you need to read the instruction on the kit. This varies between 3 to 5 minutes. Again there is variation in the way tests have to be conducted depending on the manufacturers.

Some tests say you can pee directly on the stick, others ask you to pee in a cup and then drop in the stick. Some ask you to hold the stick in a certain way while others may recommend to keep it on a counter in a certain direction. Hence, it is very crucial to read the instructions to understand “the how to do the test” exactly. Otherwise, the result might be erroneous. You cannot control the appearance of evaporation line on the Pregnancy test result window but you can definitely learn how to identify a positive test result line from an evaporation line.

[Read : How Soon To Take The Home Pregnancy Test?]

What Do Evaporation Lines Look Like?

The evaporation line begins to appear when the urine in the test area begins to dry. Evaporation line is a faint colorless or grey line but not always. There are some evaporation lines that do have color. However, the color of evaporation line is very faint. If you are not aware of evaporation line, you may think you are pregnant and when the doctor does not confirm your pregnancy, it will leave you disappointed.

How Can You Avoid Formation of Evaporation Lines?

Normally the complete reaction time of the pregnancy test is not more than 5 minutes. To ensure that your results are accurate, you must check the reading within the specified time limit as mentioned in your instruction booklet that comes with the kit. It is recommended to avoid taking the reading after the specified time is over as there is a possibility that the evaporation lines may have appeared, irrespective of the brand you use. If you keep it for a while and then read it, you might get false hopes that you might be pregnant.

[Read : What Does A Faint Line On Pregnancy Test Mean?]

How Can You Tell a Faint Line From an Evaporation Line?

confused women with pregnancy test

Another important point to note here is to not confuse the evaporation line with a faint test line that appears when the reading is taken within the stipulated time. Well, for some reasons the test line doesn’t appear dark and these could be:

  • If you test too early in the cycle, the hCG level may be low. In such cases, it is better to wait for a couple of days more and take the test again.
  • Sensitivity levels vary across brands and hence it is advisable to go for brands with higher sensitivity levels for accurate results.
  • Some urine samples may be diluted due to frequent urination or consumption of more liquids the night before. It is therefore recommended to take the first sample of urine as the hCG levels are at the highest.
  • Sometimes chemical pregnancy could be the cause for a faint line. It is a condition where the fertilized egg is implanted and therefore hCG is produced, but this is soon followed by a miscarriage.

Sometimes, we may not be aware of the difference in lines and might be celebrating until a visit to the doctor who confirms that the test was incorrect. Therefore, be patient, read the instructions on the booklet carefully and perform the test a couple of days after missing the period for accuracy and of course the good news!!

Read Also: Prega News Pregnancy Test – Use, Accuracy, Interpreting The Results

Editorial Team,

With a rich experience in pregnancy and parenting, our team of experts create insightful, well-curated, and easy-to-read content for our to-be-parents and parents at all stages of parenting.Read more.

Responses (0)

Please check a captcha

Want curated content sharply tailored for your exact stage of parenting?

Discover great local businesses around you for your kids.

Get regular updates, great recommendations and other right stuff at the right time.


Our site uses cookies to make your experience on this site even better. We hope you think that is sweet.