A urine test is a common medical diagnostic procedure used to check for various health conditions. Modern at-home urine test kits often come with indicators like colored dots that provide an easy way to understand the test results.
One of the most common indicators is a green dot on a urine pregnancy test kit. But a green dot may also appear on general urine test strips used to check for infections, diabetes, and other conditions. Here is a detailed look at what a green dot typically indicates on different types of urine tests.
Green Dot on Pregnancy Test
A pregnancy test detects the presence of the human chorionic gonadotropin (hCG) hormone in urine. This hormone is produced by the placenta shortly after fertilization occurs. Most at-home urine pregnancy kits require you to collect a urine sample and dip the test stick into the cup for a few seconds. The stick has absorbent pads that wick up the urine. Chemical reactants on the pads react to the presence of hCG, producing a visible color within a few minutes.
On most pregnancy test kits, a green dot or line indicates a positive result – that pregnancy hormones were detected in the urine sample. This means you are likely pregnant. The green color provides a clear, easy-to-interpret indicator that conception has occurred.
Some test kits may use a different color like pink or blue to indicate pregnancy instead of green. But green positive results are very common. The shade of green can vary from a pale, light green to a more blue-green teal color.
A green dot on a pregnancy test may also indicate:
- The test is working properly when urine is absorbed
- The hCG detection chemicals are active
- The test result is definitive, not faint or questionable
Instead of a green dot, some pregnancy test kits display lines, a plus sign, or the words “Pregnant” or “Positive” to indicate pregnancy. But the meaning is the same – hCG was detected based on the urine sample.
How Soon After Conception Can a Test Show Positive?
Most pregnancy tests can detect hCG levels in urine very early on, as soon as 1-2 weeks after conception. Here is a timeline of when the green dot positive may appear:
- About 7-10 days after fertilization – enough hCG may be present for a very sensitive test to show positive.
- By 2 weeks – over 90% of tests will detect the early rise in hCG levels.
- By 3-4 weeks – virtually all tests will detect pregnancy hormones and show a positive green dot.
So if you get a positive within 1-2 weeks of having unprotected sex around your ovulation date, it means you are likely pregnant. The green dot indicates the urine test chemically detected hCG.
What Does a Negative Result Look Like?
If no green dot or other positive line appears within the result window of the pregnancy test, it means a negative result. The most common negative result is a single red line in the result window. The red line indicates the test is working properly. A lack of green line means no hCG was detected in your urine.
A negative result when your period is late is not necessarily definitive. Some reasons you may get a negative urine test but still be pregnant include:
- Testing too early before enough hCG is produced
- Drinking too much fluid before testing, diluting the hCG concentration in urine
- Using expired test kits with inactive reagents
- Having a less sensitive brand of test
- Incorrect urine sample collection or test procedure
If pregnancy is still suspected after a negative urine test, repeat testing in a few days. Or have a quantitative hCG blood test done by your doctor, which is more accurate than a urine test.
Green Dot on General Urine Test Strip
Besides pregnancy tests, a green dot may also appear on general urine test strips. These strips contain multiple pads that change color to indicate levels of various substances and factors in a urine sample, such as:
- Leukocytes – white blood cells
- Nitrites
- Protein
- Glucose – sugar
- Ketones
- Bilirubin
- Blood/hemoglobin
- pH – acidity
- Specific gravity – concentration
- Urobilinogen
The green dot on a test strip may correspond to the reagent pad for nitrites, leukocytes, protein, or other markers. A green color indicates an abnormal level of that substance was found in the urine. The test kit instructions will specify which pad the green dot appears on for positive results.
Nitrites
Nitrites in urine often indicate a urinary tract infection (UTI). Bacteria such as E. coli that cause UTIs release enzymes that convert nitrates in urine to nitrites. So a green dot on the nitrite pad generally means a positive test for a UTI.
Leukocytes
Leukocytes are white blood cells. A green dot on the leukocyte pad means elevated leukocytes were found, which also may indicate an infection. Green on this pad may also indicate kidney disease, bladder inflammation, or other conditions.
Protein
Protein in urine is abnormal and usually a sign of kidney damage or disease. Causes of proteinuria include:
- Kidney infection
- Diabetes
- High blood pressure
- Glomerulonephritis – inflammation of kidney filters
So the green dot indicates positive results for excess protein spilled into the urine by diseased kidneys.
Other Pads
On some test strips, a green dot may also signify positive results for glucose, ketones, or other markers. The green means an abnormally high level was detected. Specifics will depend on which pad changes to green per the test instructions.
Green Dot Instead of Expected Color
Urine test strips are designed to change certain pads to specific colors based on positive results. For example, a blue dot may be the expected positive color for proteins rather than green. Or red for blood.
If the green dot appears on a pad that should be turning a different color, it may indicate:
- Expired chemical test reagents
- An invalid test
- A false positiveresult
- Incorrect urine sampling
- Failure to follow test instructions properly
So if the dot is green but should be blue or red based on the instructions, the test should be repeated. And if green continues to appear on the wrong pads, it likely means the test strip is defective.
Green Dot that Appears Late
Positive dots should appear within the time specified in the urine test instructions. For pregnancy tests, results are usually read in 3-5 minutes when the green dot will be visible.
If a faint green dot appears much later, such as hours after taking the urine test, it may be an “evaporation line.” The urine starts evaporating from the result window, leaving traces of the reagents behind. As the urine dries, a faint green LINE rather than defined DOT may appear.
An evaporation line is not a true positive result – it does not mean you are pregnant or that abnormal levels of other markers were reliably detected. The test should be repeated with a new kit for accurate results.
What Other Colors May Appear?
Here are other dot colors that may show up on urine test strips and their typical meaning:
- Red – Blood, hemoglobin, abnormal pH levels
- Purple – Abnormal bilirubin levels
- Orange – Nitrites, Urobilinogen
- Blue – Proteins
- Yellow – Ketones
The color bar on the test package will highlight which pad corresponds to each color for positive results.
Summary of Green Dot Meanings
In summary, a green dot on a urine test typically indicates:
| Test Type | Green Dot Meaning |
|---|---|
| Pregnancy test | Positive for pregnancy hormone hCG |
| Nitrites test | UTI likely present |
| Leukocytes test | Infection, inflammation, or other condition |
| Protein test | Kidney disease or damage |
| Glucose test | High blood sugar |
| Ketones test | Ketoacidosis likely |
| Bilirubin test | Liver function impairment |
| Blood test | Blood or hemoglobin detected |
Conclusion
When reading urine test results, a green dot typically signals a positive test for whichever substance the corresponding reagent pad is designed to detect. On a pregnancy test, it means you are likely pregnant. And on general urine test strips, it indicates abnormal levels of certain biomarkers associated with various health conditions were found.
Being familiar with how to interpret the green dot and other colored dots that may appear can help you understand these common urine tests. Be sure to always follow the test instructions closely and repeat the test if the colors that appear don’t match the expected results.