What Is hCG? Testing, Levels, and Health Insights

What Is hCG?

hCG stands for human chorionic gonadotropin. It’s a hormone your body starts making shortly after a fertilized egg attaches to the wall of the uterus.

This hormone plays an important role in the early stages of pregnancy. It helps maintain the uterine lining and supports the embryo as it develops. It also signals the body to stop menstruation during pregnancy.

Doctors often check hCG levels to confirm pregnancy. But it’s not just about pregnancy. In some cases, hCG is measured to look into possible pregnancy-related problems, fertility treatments, or health conditions like tumors that can raise hCG levels.

When Is hCG Testing Recommended?

Doctors may suggest an hCG test for different reasons. This test helps check for pregnancy and can also give clues about other health conditions.

You might need an hCG test in the following cases:

• To confirm pregnancy: After a missed period, an hCG test can confirm if you're pregnant.
• To estimate how far along the pregnancy is: Measuring hCG levels can help figure out the stage of early pregnancy.
• To check for ectopic pregnancy: If a pregnancy is growing outside the uterus, hCG levels may rise differently.
• To monitor a possible miscarriage: Falling hCG levels can be a sign of a pregnancy loss.
• After a miscarriage or abortion: To make sure hCG levels return to zero, meaning pregnancy tissue is no longer present.
• To monitor a molar pregnancy: This rare condition causes abnormal growth of cells in the uterus and affects hCG levels.
• During fertility treatments: To track ovulation and confirm if the treatment led to pregnancy.
• To check for tumors: In rare cases, certain tumors produce hCG, and the test helps detect them.

How Is hCG Testing Conducted?

hCG is usually measured through a blood test or urine test. Both methods check for the presence of the hormone, but blood tests can also show the exact amount of hCG.

You’ve probably heard of pregnancy tests, they’re a common way people first learn about hCG. Home pregnancy tests are a type of urine test that checks if hCG is present. If it is, the test usually shows a positive result.

There are two main types of hCG tests:

• Qualitative hCG test:  This test gives a simple answer: yes or no. It checks if hCG is present to confirm pregnancy.
• Quantitative hCG test (also called beta hCG): This test shows the exact level of hCG in your blood. It’s useful for tracking how the levels rise or fall over time.

Do You Need to Prepare for the Test?

You can eat and drink normally before the test unless your doctor gives specific instructions.

For a urine test at home, using the first urine of the day may give the most accurate result.

What Are the Normal hCG Levels?

hCG levels change quickly during the first weeks of pregnancy. They usually double every 2 to 3 days in early pregnancy, then level off after the first trimester.

Here’s a general guide to expected hCG levels by weeks since the first day of your last menstrual period (LMP):

Non-pregnant women and men can also have small amounts of hCG in their bodies. In non-pregnant individuals, normal levels are usually less than 5 mIU/mL.

Urine tests simply check whether hCG is present or not, rather than showing a number. Most home pregnancy tests are designed to detect hCG levels starting at 20–25 mIU/mL.

Note: The units of measurement and the normal ranges can differ depending on the laboratory and the specific methods used.

Levels outside this range do not always mean something is wrong. Doctors often look at how your levels change over time rather than relying on one number alone.

What Do Abnormal hCG Levels Mean?

Abnormal hCG levels, either too high or too low, can sometimes signal a health issue. But one test alone doesn’t tell the whole story. Doctors usually track how levels change over a few days to understand what’s happening.

hCG High Levels

When hCG levels are much higher than expected for the pregnancy stage, it may point to a few different conditions.

Possible causes include:

• Multiple pregnancy: Carrying twins or triplets naturally leads to higher hormone levels.
• Miscalculated pregnancy dates: If the pregnancy is farther along than thought, hCG may appear high.
• Molar pregnancy: A rare condition where abnormal tissue grows in the uterus instead of a baby.
• Certain tumors: Some types of tumors can produce hCG, even when a person is not pregnant.

If your hCG levels are high:

• Don’t panic, request a follow-up test to check trends.
• Ask for an ultrasound to confirm the pregnancy's progress.
• Follow your doctor’s advice on any further testing.
• Avoid self-diagnosing based on one result.

hCG Low Levels

When hCG levels are lower than expected, it may suggest a problem with the pregnancy or an error in timing.

Possible causes include:

• Ectopic pregnancy: The pregnancy grows outside the uterus, often in a fallopian tube.
• Miscarriage: Falling hCG levels may be an early sign of a pregnancy loss.
• Blighted ovum: A fertilized egg implants in the uterus but doesn’t develop into an embryo.
• Miscalculated pregnancy dates: The pregnancy may be earlier than expected, which explains the lower hCG.

If your hCG levels are low:

• Repeat the test after 48-72 hours to see if levels rise.
• Share any symptoms like cramping or bleeding with your doctor.
• Consider an ultrasound to check the pregnancy’s location and status.
• Stay in touch with your healthcare provider and follow up as advised.

Which Specialist Should You Consult?

For questions about hCG levels, the right specialist depends on your situation:

• Obstetrician/Gynecologist (OB-GYN) - Best for pregnancy-related concerns and hormone testing.
• Fertility Specialist - Helpful if you’re going through fertility treatments.
• Primary Care Doctor - Can guide you on next steps and refer you to the right expert.
• Oncologist - In rare cases, if hCG is related to tumors or abnormal growths.