Complement C3

Optimal Result: 82 - 167 mg/dL.

Measurements of serum complement components C3 is useful in the diagnosis and monitoring of immune complex disease e.g. SLE (Systemic lupus erythematosus) and some blood associated infectious diseases. Complement concentrations are acute phase proteins and may be normal, despite complement consumption, in some inflammatory and infective disorders. C3 alone is often decreased in infectious disease (septicaemia, endocarditis).

Measurement of serum complement is useful in the monitoring of specific immune complex diseases e.g SLE and infectious diseases post streptococcal disease, subacute bacterial endocarditis.

Though genetic deficiencies of C3 are exceedingly rare, deficiencies in other components which are more common (though still very rare) can result in low C3.

The normal adult range for C3 is 90-180mg/dl.


What does it mean if your Complement C3 result is too low?

Values <1mg/dl can be found in active immune complex disease, septicaemia, bacteraemia, post streptococcal glomerulonephritis or diseases associated with nephritic factor. Low levels of C3 associated with low levels of C4 demonstrate classical pathway activation and strongly suggest immune complex disease. They are found most commonly in cases of active SLE (Systemic lupus erythematosus). Low levels of C3 associated with normal levels of C4 demonstrate alternative pathway activation suggestive of infectious disease or nephritic factor activity.

Although in some long standing SLE patients C3 levels remain low, which does not necessarily denote active disease, a sudden fall in levels does usually indicate exacerbation of disease activity and a risk of renal damage.

What does it mean if your Complement C3 result is too high?

The complement C3 test results vary depending on the person's health history, age, and sex. The normal range for the complement C3 test is 80 to 160 milligrams per deciliter or 0.8 to 1.6 grams per liter.

The complement levels in the blood rise after an injury or injection, but when the complement system responds to a disease, your complement levels go down.

High C3 complement levels indicate inflammation in the body. The inflammation could be due to ulcerative colitis or other acute diseases like sarcoma, leukemia, or Hodgkin's Lymphoma.

These are all different types of cancer. However, increased levels of C3 are not the main indication of cancer.

Elevated C3 complement levels are also observed in people with diabetes. Therefore, other tests are necessary to confirm the diagnosis.

Higher-than-normal levels of C3 proteins can indicate that you’ve just had an infection and your immune system is responding to it. 

If you get treatment for a disease such as lupus, high levels of C3 indicate that the treatment works. 

Increased C3 levels may also be a sign of:

- Heart attack (myocardial infarction) and other heart problems.
- Sarcoidosis (inflammatory disease).
- Thyroid disease
- Ulcerative colitis

If C3 values are abnormally high or low, additional tests or procedures may be ordered to narrow or confirm the suspected cause.

10 000+ happy customers
100% satisfaction
★ ★ ★ ★ ★ customer support

Understand blood, stool, and urine medical results from all your laboratories.

Upload Your Personal Results

Upload Personal Results

For professional account plans go here

for professional account plans go here

Monthly plan

Annual plan

Own it for life

  • Subscription
  • Data entry service included

    Data entry service

    Our exclusive data entry service is a convenient way to get your results into your private dashboard. Simply attach an image or a file of your lab test results, and one of our qualified data entry team members will add the results for you. We support all sorts of files, whether PDFs, JPGs, or Excel. This service is excellent whether you have a lot of reports to upload or are too busy to do the data entry yourself.

  • Instant interpretation
  • Use free data entry form

    Free data entry form

    We strive to make the data entry process easy for you. Whether by offering dozens of templates to choose from that pre-populate the most popular laboratory panels or by giving you instant feedback on the entered values. Our data entry forms are an easy, fast, and convenient way to enter the reports yourself. There is no limit on how many lab reports you can upload.

  • 4000+ biomarkers explained
  • Nutrition recommendations
  • Cancel anytime


$15 /month

billed every month

  • monthly
  • $15 per report
  • ✓ Instant interpretations
  • ✓ 4000+ biomarkers explained
  • ✓ Nutrition recommendations
  • ✓ Free data entry form
  • ✓ Unlimited data
  • ✓ $15 data entry service
  • ✓ Cancel anytime

Most popular

Data entry included


$79 /year

$6.60/month billed annually

  • yearly
  • 5 reports free
  • ✓ Instant interpretations
  • ✓ 4000+ biomarkers explained
  • ✓ Nutrition recommendations
  • ✓ We enter 5 reports for you
  • ✓ Yearly subscription
  • ✓ Cancel anytime

Data entry included


$250 /once

own it for life

  • pay once
  • 10 reports free
  • ✓ Instant interpretations
  • ✓ 4000+ biomarkers explained
  • ✓ Nutrition recommendations
  • ✓ We enter 10 reports for you
  • ✓ No subscription
  • ✓ Dedicated support
  • ✓ Unlimited access

Are You a Health Professional?

Get started with our professional plan

Welcome to Healthmatters Pro.

Save time on interpreting lab results with the largest database of biomarkers online. In-depth research on any test at your fingertips, all stored and tracked in one place. Learn more

Pro Monthly Plus

for health professionals

  • ✓ Track multiple clients results
  • ✓ No setup fees
  • ✓ No hidden costs
  • ✓ Instant interpretations
  • ✓ 4000+ biomarkers explained
  • ✓ Includes data entry service
  • ✓ Personal training and support
  • ✓ Cancel anytime

$75 per month

Use promo code to save 10% off any plan.

We implement proven measures to keep your data safe.

At HealthMatters, we're committed to maintaining the security and confidentiality of your personal information. We've put industry-leading security standards in place to help protect against the loss, misuse, or alteration of the information under our control. We use procedural, physical, and electronic security methods designed to prevent unauthorized people from getting access to this information. Our internal code of conduct adds additional privacy protection. All data is backed up multiple times a day and encrypted using SSL certificates. See our Privacy Policy for more details.