H. pylori IgG: What Your Result Means

What is H. pylori IgG?

Helicobacter pylori is a bacterium that lives in the stomach lining and is the leading cause of peptic ulcers and a major risk factor for gastric cancer. The IgG antibody test detects the immune system's memory of the infection. Because antibodies stay for years, a positive result confirms exposure but cannot tell whether the bacteria is still active today — which is why stool antigen or breath tests (which detect the live bacteria) follow up when needed.

Typical reference interval: Reported as negative or positive, often with a quantitative value (commonly in U/mL or as an index). A negative result means no detectable antibody response to H. pylori — the reassuring screening outcome. Interpret with your lab's cutoff.. Laboratories differ — the interval printed on YOUR report always governs.

If your H. pylori IgG is high

Common reasons H. pylori IgG runs above the reference interval:

• Past or present H. pylori infection — the only real reason this antibody is present — exposure produces lasting IgG
• Chronic stomach infection — many people carry H. pylori for years with no symptoms at all
• Recent antibiotic-eradication attempt — antibodies can persist for months after the bacteria is cleared

If your H. pylori IgG is low

Common reasons H. pylori IgG runs below the reference interval:

• No prior exposure — a negative result is the expected finding for most people — no H. pylori antibody response
• False-negative window — early in infection (before antibodies form) or with certain immune conditions, the test can under-report

Symptoms worth knowing

The antibody causes no symptoms. H. pylori itself is often silent — that is why it spreads so widely. When it does cause trouble, the signs are stomach-based: burning upper-abdominal pain, nausea, bloating, and sometimes ulcers that bleed.

What usually happens next

1. A positive H. pylori IgG is a reason to confirm whether infection is ACTIVE — a stool antigen or urea breath test does that
2. Confirmed active infection with symptoms is treated with a clinician-directed combination therapy — never self-medicated
3. A negative result after symptoms have been treated usually means the course worked

Frequently asked questions about H. pylori IgG results