What is the VDRL test?

The VDRL (Venereal Disease Research Laboratory) test is a widely used blood screening test for syphilis. It is accessible at most laboratories worldwide, even without a doctor's referral, making it one of the most common STD screening tools available.

What does a VDRL false positive mean?

A VDRL false positive, also called a Biological False Positive (BFP) reaction, occurs when the test returns a positive result in a person who does not actually have syphilis. This affects approximately 1–2% of people tested and is typically seen at low dilution levels of less than 1:8.

What are the causes of a VDRL false positive test?

Common causes of a VDRL false positive include laboratory error or poorly trained technicians, autoimmune diseases such as SLE (Systemic Lupus Erythematosus) and Rheumatoid arthritis, febrile illnesses such as malaria, tuberculosis, and filariasis, pregnancy, recent vaccination, aging, drug addiction, liver disease, and malignancy.

Can pregnancy cause a false positive VDRL test?

Yes. Pregnancy is one of the recognized causes of a biological false positive VDRL result. Pregnant women who test positive on VDRL screening should undergo further confirmatory testing to rule out true syphilis infection.

Can a recent vaccination cause a false positive VDRL?

Yes. Recent immunization with any type of vaccine is an important cause of false positive VDRL results and should always be mentioned in the medical history when evaluating an unexpected positive syphilis test.

What should I do if my VDRL test is positive but I don't have syphilis symptoms?

If a biological false positive is suspected, a thorough medical history and further confirmatory investigations are needed to identify the true cause. It is recommended to repeat the VDRL test at 10 weeks, as most false positive results will become non-reactive by that time. Always consult a physician for proper evaluation.

VDRL False Positive Test: Causes and What to Do

最后更新： 2026年5月18日

Soarawee Weerasopone，泌尿科医生

曼谷医院总部，曼谷

Samitivej Sriracha 医院, 春武里府

LINE联络

VDRL test or Venereal Disease Research Laboratory test is a very common syphilis screening test. The problem will be occurred when VDRL turn positive without any suspicious of syphilis infection, we called this incident “生物假阳性” or BFP reaction. Today we will discuss on this BFP phenomenon.

遇到这个问题的患者会影响他们的精神和日常表现。

BFP phenomenon has been reported around 1-2% of an incidence. BFP usually showing out in a low dilutions (<1:8). Here are the possibilities of BFP phenomenon.

Causes of VDRL False positive phenomenon

Laboratory error from unwell-trained technicians
Autoimmune diseases – SLE or Rheumatoid arthritis
Febrile illness – Malaria, Tuberculosis, Filariasis
怀孕
近期免疫
老化
毒瘾
肝病
恶性肿瘤

VDRL false positive test sometimes can be detected in Pregnancy.

Once BFP phenomenon is suspected, a careful history taking and proper investigation must be done. It would be recommended to retest VDRL again at 10 weeks — most cases will turn nonreactive at that time. Any questions, you can discuss with your trusted physicians, or it would be my honor if you can text me. Take care!

你可以访问我的官方主页这里.

常见问题解答

Q1: What does a VDRL false positive result mean?

A VDRL false positive result means the test shows a reactive result without the person actually having a syphilis infection. This is known as a Biological False Positive (BFP) reaction, which occurs in approximately 1-2% of cases. BFP results typically appear at low dilution levels (less than 1:8) and require further investigation to identify the true underlying cause.

Q2: What conditions can cause a VDRL false positive?

Common causes of VDRL false positive include autoimmune diseases such as SLE and rheumatoid arthritis, febrile illnesses such as malaria and tuberculosis, pregnancy, recent vaccinations, aging, drug addiction, liver disease, and malignancy. Laboratory error from untrained technicians is also an important consideration when a false positive is suspected.

Q3: How can I confirm whether my VDRL positive is a true or false positive?

When a false positive is suspected, a confirmatory treponemal test such as TPHA or FTA-ABS should be performed. If the confirmatory test is negative while VDRL is positive, a BFP reaction is highly likely. Retesting VDRL at 10 weeks is also recommended, as most BFP cases will revert to non-reactive within this timeframe.

Q4: Should I be worried if my VDRL test comes back positive?

A positive VDRL result should not cause immediate panic, as false positives do occur. However, it should always be evaluated by a physician rather than ignored. A thorough clinical history, physical examination, and confirmatory testing are necessary to determine whether the result represents true syphilis infection or a biological false positive.

Q5: Can pregnancy cause a false positive VDRL?

Yes. Pregnancy is one of the recognized causes of a VDRL biological false positive reaction. Pregnant women who receive a positive VDRL result should be evaluated with a confirmatory treponemal test to differentiate a true syphilis infection from a pregnancy-related false positive, as appropriate treatment during pregnancy is critical for fetal health.

If you have received a positive VDRL result and are unsure how to interpret it, Dr. Soarawee Weerasopone offers specialist consultations in sexual health at Bangkok Hospital Headquarters. 预约咨询.

**免责声明：** 本内容由曼谷医院总院的认证泌尿科医生 Soarawee Weerasopone 医生撰写和审阅。本内容仅用于教育目的，不构成医疗建议。在开始任何医疗治疗前，请务必咨询合格的医疗专业人士。.

医学撰写与审阅： 素瓦瑞·维拉宋蓬医生（Pom医生）— 曼谷医院总部认证泌尿科医生。国际学者：贝勒医学院（美国）· 顺天堂大学（日本）· 长庚纪念医院（台湾）。.