Blood Test for TB: Symptoms, Purpose, Procedure, and Results
Medically Reviewed By
Prof. Ashok Rattan
Written By Muskan Taneja
on Feb 3, 2025
Last Edit Made By Muskan Taneja
on Jul 19, 2025
Do you know India accounts for 25% of the global TB burden? Tuberculosis, or TB, is a major public health challenge in the country. In 2023, India was estimated to have had over 28 lakh new cases of TB. A blood test for TB can curb this prevalence, help manage symptoms on time, and prevent major complications.
The TB blood test is called the Interferon Gamma Release Assay (IGRA). It measures your immune system’s reaction to TB proteins. This blog will provide detailed information about a blood test for TB.
What is a TB Blood Test?
The blood test for tuberculosis checks for the Mycobacterium tuberculosis complex, which causes tuberculosis. In India, the test is called an Interferon Gamma Release Assay (IGRA) or TB Quantiferon gold test. A TB blood test is an easy, convenient, and effective method of diagnosing the infection.
The blood test for TB in India is popular with several names:
You can book the TB blood test from Redcliffe Labs. They have a wide area network of over 3600 tests at an affordable price across India.
11 Symptoms of TB Test
Plenty of signs and symptoms show the need for a TB test. The following are some common symptoms of TB.
- Persistent cough
- Fever
- Weight loss
- Chronic fatigue
- Shortness of breath
- Pain in the bones
- Skin infections
- Jaundice (yellow skin or eyes)
- Blood in the urine or stool (poop)
- Chest pain
- Night sweats
Tuberculosis usually attacks the lungs. However, it’s a contagious bacterial infection that can also spread to other body parts, including the kidneys, spine, brain, and lymph nodes. Therefore, the symptoms of TB may vary.
Who Needs a TB Blood Test?
Along with the symptoms, various factors indicate the need for a TB blood test. These include:
- A person has been in close contact with someone who has active TB or lived in a country where TB is common.
- A person working in a healthcare facility, homeless shelter, nursing home, or prison as these are at high risk of TB.
- A person who has traveled to a TB-prone country.
- A person with a weak immune system or infected with certain health conditions like HIV.
- A person who experienced symptoms of TB: chest pain, fever, weight loss, and night sweats for over three weeks.
- A person infected with a health condition like diabetes, an organ transplant, or use illegal drugs that are injected with needles.
What is the Procedure for the TB Blood Test?
The TB blood test is similar to other blood tests. Blood samples are drawn to diagnose TB, and the bacteria Mycobacterium tuberculosis is detected. After booking the TB blood test from Redcliffe Labs, a phlebotomist will visit your home to collect the samples.
- They will clean the skin with an alcoholic substance to prevent the risk of infections.
- They will tie a band on your upper arm to make veins appear while preventing blood flow.
- They will insert a small needle in the vein to collect blood.
- They will transfer the collected blood into a test tube and put a cotton swab on the punctured site to prevent excessive blood flow.
- Label the test tube with your details: name, time, and sample collection location.
- Once the procedure is complete, they will transfer the collected blood sample into a laboratory for analysis. You will receive the test reports within 72 hours.
Are there any Risks Linked to the Blood Test for Tuberculosis?
The TB blood test usually has no major risk linked. However, the process involves inserting a needle, which may cause certain risks.
A person may experience:
- Pain
- Bruising
- Bleeding
- Lightheadedness
- Infection
* These signs disappear in no time. However, if they last for long, seek medical consultation.*
Understanding the Results of TB Blood Test
The blood test for TB will indicate either a positive or negative result. A positive TB test result means you have a TB infection. Meanwhile, a negative TB test result means you don’t have a TB infection. A doctor may recommend additional tests for proper diagnosis and understanding.
What if the TB Test Reports are Positive?
A positive TB blood test result means you may have TB germs in your body. Most people with TB positive have latent TB infection. A latent tuberculosis infection (LTBI) is when your body has tuberculosis bacteria, but it doesn’t cause any symptoms. In simple words, most people with tuberculosis are asymptomatic. People with LTBI may spread it to other people.
A healthcare professional may recommend medications to treat LTBI (Phase 1). Delaying treatment may lead to acute TB disease (Phase 2). Here is a classification of Phase 1 and Phase 2.
| Acute TB Disease | Latent TB Infection |
| TB germs are active and spread from one person to another. They may damage tissues in your body. | TB germs are not active in your body. This phase may last for a very long time. |
| A doctor may recommend special tests to diagnose the cause while you may feel sick. | A doctor may perform a chest X-ray while you don’t experience any symptoms or feel sick. |
| It is contagious, i.e., it can spread through cough, sneeze, and even talking. | It is not infectious. |
| It can be treated with certain medications for a minimum of 6 months. | Usually, they require one medicine for 9 months. |
Treatment for Tuberculosis
If the blood test for TB indicates latent TB infection, your healthcare provider may suggest certain pharmaceutical medications., which continue for three or four months.
A doctor may recommend a combination of antibiotics for 4 to 12 months to treat tuberculosis (TB). The treatment process depends on the affected organ.
- Antibiotics- A doctor may recommend antibiotics for treating tuberculosis. It includes rifampin, pyraziamide, ethambutol, adn isoniazid.
- Protein-rich Diet- Add more protein to your diet, like lean meat, poultry, fish, beans, lentils, nuts, and eggs. They can help with recovery.
- Include Vitamin B6 in your Diet- Healthcare providers give vitamin B6 or pyridoxine to patients at risk of neuropathy.
The duration of tuberculosis treatment differs based on active, latent, and drug-resistant.
- Treatment for active TB can take 4, 6, or 9 months, depending on the treatment plan.
- Treatment for Latent TB can take 3 to 6 months.
- For drug-resistant TB, there is no treatment, and it is more complex than standard TB.
Book The Blood Test for TB From Redcliffe Labs!
Redcliffe Labs offers a blood test for TB called Quantiferon TB IGRA test, which detects mycobacterium tuberculosis bacterium. You can book the tests through the official website or mobile app.
Steps to Book These Tests from Redcliffe Labs
- Visit the website, www.redcliffelabs.com
- Search for the specific test you need.
- Click on ‘Book Now.’
- Fill out the required details (address and time).
- A phlebotomist will visit your home for a sample collection.
- Receive the test reports within no time.
