What Does a Faint Line on a Rapid Test Mean? Skip to main content Close Select your preferred language English عربى 简体中文 繁體中文 فارسي עִברִית 日本語 한국어 Русский Español Tagalog Menu Close Call 1-800-CEDARS-1 toggle search form Close Los Angeles, 16 August 2022 09:00 AM America/Los_Angeles Health com Why Even a Faint Line on Your Rapid Test Still Means You re COVID- Positive What's the difference between a faint line and a bold line on a rapid COVID-19 test? Cedars-Sinai's Eric Vail, MD, explains. Photo by Getty. Gloved hand holding rapid home COVID-19 antigen test kit showing a positive result. Lateral flow test. Blue Background. Health.com recently interviewed Eric Vail, MD, director of Molecular Pathology, about the at-home antigen test for the virus that causes COVID-19 and how it determines whether the virus is inside the body and, if so, how much virus is there. At-home antigen tests work by detecting whether the virus is found in testers’ nasal secretions, Vail told Health.com. If the window on the testing stick shows two lines, the tester is positive for COVID-19. The opaqueness of the lines also can indicate more, Vail said. If the line is fainter, the patient is likely to be less sick, less infectious, or might be nearing the end of infection, Vail said. A faint line also can mean the tester didn’t swab well enough to provide a good test sample. A brighter line indicates the patient has more virus in their body and is likely to be sicker and more infectious. Still, whether the line or lines are bright or faint, two lines still mean positive, one line still means negative, and the safety precautions remain the same: "Five days of [isolation] and then five days of masking if you have no symptoms,” before going back to your normal routine, Vail said. After following those guidelines from the U.S. Centers for Disease Control and Prevention (CDC), there’s still the possibility that someone could test positive. On day six, about 50 percent will still test positive. “Does that mean they're still infectious? We don't know," Vail told Health.com. That uncertainty is why the CDC recommends five more days of isolation. The chance of getting a false positive is low with at-home tests, so following the antigen test directions and CDC guidelines to the letter prevents the possibility of spreading the virus to others. Click here to read the complete article from Health. Related Stories RSS feed - Related Stories (opens in new window) View all headlines - Related Stories HealthDay Black Women Less Likely to Get Laparoscopic Fibroid Surgeries October 07, 2022 09:00 AM America/Los_Angeles HealthDay recently interviewed Rebecca J. Schneyer, MD, a resident in the Obstetrics and Gynecology Residency Program at Cedars-Sinai, about a study she led that found Black and Hispanic women were less likely than white women to receive minimally … Read more KCRW Want New Omicron Booster Wait at Least 2 Months After Last Shot October 06, 2022 09:00 AM America/Los_Angeles KCRW program Press Play recently featured Rita Shane, PharmD, vice president and chief pharmacy officer at Cedars-Sinai, discussing who qualifies for the updated COVID-19 booster and how long patients must wait before getting the shot.The Centers … Read more ABC 7 Spider-Man Swings by 4-Year-Old Leukemia Patient s Birthday Party at Cedars-Sinai September 30, 2022 09:00 AM America/Los_Angeles ABC 7 recently profiled Cedars-Sinai patient Jabari Henley, who celebrated his fourth birthday with a special superhero at Guerin Children's newly opened inpatient facility.The Lifedriven Foundation helped throw Henley a surprise party in the Guerin … Read more Show previous items Show next items Contact the Media Team Email: [email protected] Contact Marni Usheroff marni.usheroff@cshs.org Share this release Health com Why Even a Faint Line on Your Rapid Test Still Means You re COVID- Positive Share on: Twitter Share on: Facebook Share on: LinkedIn Search Our Newsroom Social media Follow us on Twitter (opens in new window) Visit our Facebook page (opens in new window) (opens in new window) Visit our Youtube profile (opens in new window) Latest news 07 Oct 2022 - HealthDay Black Women Less Likely to Get Laparoscopic Fibroid Surgeries 07 Oct 2022 - Faculty Publications: Sept. 29-Oct. 6 07 Oct 2022 - Fine-Tuning Organ-Chip Technology 06 Oct 2022 - KCRW Want New Omicron Booster Wait at Least 2 Months After Last Shot 05 Oct 2022 - Cedars-Sinai Schedules Free Flu Vaccine Clinics 04 Oct 2022 - Cedars-Sinai Showcases Hispanic and Latinx Art Newsroom Home