About Careers Internship MedBlog Contact us

Lung Tuberculosis

Last Updated on Jul 21, 2023
Font : A-A+

How does Tuberculosis Spread?

Tuberculosis infection generally involves the lung tissue and is called pulmonary tuberculosis.


Pulmonary TB can be of two types based on whether the patient produces the TB germs in his sputum or not-

  • Patients who have TB germs in the sputum are called sputum positive pulmonary TB patients.
  • Patients whose sputum is negative are called the sputum negative pulmonary TB patients.
How does Tuberculosis Spread?

Generally the sputum positive TB patients are the people who spread the disease in the community. A single infected untreated person can spread the disease to 10-15 individuals in his community.

Tuberculosis is transmitted from an infected person to a susceptible individual through airborne particles known as droplet nuclei. Tuberculosis bacteria are not transmitted by surface contact. This means touching cannot spread tuberculosis unless the bacteria are breathed in.


The infectious droplet nuclei, 1–5 microns in diameter, are tiny water droplets with the bacteria that are released when people with active pulmonary or laryngeal tuberculosis cough, sneeze, laugh, shout, speak etc. The droplet nuclei remain suspended in the air for up to several hours.

Infection with tuberculosis germs does not denote disease. The initial infection might not be associated with any symptoms. The germs are harbored in the body and they lie in the dormant state. 10% of the people who harbor the infection develop the disease in a time span of 60 years.

The chances of developing tuberculosis disease in such an infected person becomes higher when the person’s immunity goes down in conditions such as diabetes, cancer, chronic illness, malnutrition, HIV or treatment with immunosuppressive drugs as in after transplant surgery.


People who are at an increased risk of tuberculosis -

  • Infants
  • Elderly people
  • People with weak immune systems due to AIDS, chemotherapy, diabetes or immunosuppressant medicines.

Please use one of the following formats to cite this article in your essay, paper or report:

  • APA

    Dr. Trupti Shirole. (2023, July 21). How does Tuberculosis Spread?. Medindia. Retrieved on Sep 22, 2023 from https://www.medindia.net/patients/patientinfo/how-does-tuberculosis-spread.htm.

  • MLA

    Dr. Trupti Shirole. "How does Tuberculosis Spread?". Medindia. Sep 22, 2023. <https://www.medindia.net/patients/patientinfo/how-does-tuberculosis-spread.htm>.

  • Chicago

    Dr. Trupti Shirole. "How does Tuberculosis Spread?". Medindia. https://www.medindia.net/patients/patientinfo/how-does-tuberculosis-spread.htm. (accessed Sep 22, 2023).

  • Harvard

    Dr. Trupti Shirole. 2023. How does Tuberculosis Spread?. Medindia, viewed Sep 22, 2023, https://www.medindia.net/patients/patientinfo/how-does-tuberculosis-spread.htm.

Do you wish to consult a Pulmonologist for your problem? Ask your question

Dr. Hiren Popat
Dr. Hiren Popat
12 years experience
View All

Post a Comment

Comments should be on the topic and should not be abusive. The editorial team reserves the right to review and moderate the comments posted on the site.



Hello sir,

I am 28 years old,

I had cough and chest pain, i consulted the doctor and he said there some fluid in my chest and removed fluid by endoscopy treatment, but they found TB bacteria in biopsy result, I started the TB treatment that akurit4 tablets for 2 months and akurit3 for 4 months, and I was feeling better.

After completed 6 months treatment I found enlarged lymb node [left side of the neck].

Doctor suggest me to remove the lymb nodes and continue akrut3 tablets

I could not continue day by day treatment with tb tablet, I had missed 4 or 5 days TB tablet in initial months of completed six months treatment - Is that big problem?
Now I am really afraid of this. I have few more doubts that i have listed below, I hope you will help me

1) Why lymb node enlarged after 6 month completed treatment?

2) How do i check if there a TB bacteria in my body? or how do i check TB bacteria increasing or decreasing in my body?

3) DB patients have any problem in future? Will TB come back in future?

4) What are the side effects of long duration TB treatment with TB tablets?


dear sir,I was going through spinal TB treatment for about 10-11 months..and Istop taking medicines after this time period.. and now I am feeling symptoms again such as weakness,loss of weight but no cough..on my upper portion of my back its something like nailing inside..I am really afraid to consult doctor again because doctor told me that their is no ways to treat TB if you stopped taking medicine without my consult..I stopped my medicine in starting of January 2015..please help me sir..my age is 25 years and I am a boy living in India


Sir, I am female aged 40 years, Indian national staying in UAE for last 10 years. Every 3 years for getting a residense visa I need to undergo medical tests to check for any infectious disease. So many years I have done tests, never faced any problem. Unfortunately very recently when I had to undergo X-ray they found some spot in my chest and suspected for TB. As instructed by health authorities I had to undergo skin test, IGRA blood test and Sputum test. Skin test and IGRA blood test has come negative. Moreover sputum test is also negative. Only test left is sputum culture test result which they said will take 42 days. I had submitted my sputum last month. I had checked yesterday for any developments with the authorities as they said you could check after 15 days post sputum submital. The result was still not available and they told to wait till end of this month for final result as 42 days will be completed. In last 6 months or may be more I never had any TB symptoms such as headache, fever, fatigue, weight loss, cough etc. I am very much worried about the final outcome which will decide whether I could continue staying in UAE or not. Can you please advice what are the chances of the test outcome. Is it possible that I am infected. Your reply will help to release my anxiety and educate other friends in such incidents.


Hi, My mother is 72yrs old.She has been having low grade fever past 2 months. Her sking TB test and TB gold blood test are positive. She suffers from weak stomach. she doesn't have any cough, has had slight weight loss, has pain in her shoulders ans base of spine. Please let me know what kind of TB is she suffering from and would she be able to sustain such strong TB medication? What can I do to help her?


My daughter aged 10years had chine of Lymphnodes enlarged rht sid of the neck and NFAC done report says single TB bacteria cell found. Then doctor started ATT, after 10days she got high fever @103 and full total rashes. Admited in hospita. The doctor says its measles.. now the treatment for ATT stoppped and LFT reports 2 levels increased. Now i am not understanding weather that correctly dignosed TB or not . And if TB confirm how to manage the LFT levels under medication.. Presently taking RCINIC KID AND PYZINA KID tabs supporting Bcomplex. Experts kindly suggest

View More Comments
Recommended Readings
Get Health and Wellness Secrets from Our Engaging eBooks
Health Topics A - Z
What's New on Medindia
Quiz on Poisoning (Advance)
Remembering Those Who Can't: World Alzheimer's Day
Tooth Discoloration
View all
This site uses cookies to deliver our services.By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Use  Ok, Got it. Close
Greetings! How can I assist you?MediBot