Disseminated tuberculosis (TB) occurs when the infection has spread through your blood to other parts of your body. This causes widespread symptoms that may include abdominal pain, night sweats, and unexplained weight loss.

Infection with the bacteria Mycobacterium tuberculosis is most notable for causing pulmonary (lung) TB. But the infection can occur in several places, such as your spine, kidney, or brain. TB that occurs outside the lungs is known as extrapulmonary TB.

Disseminated TB means the infection has spread through your blood to other parts of your body. Disseminated TB is typically both pulmonary and extrapulmonary, though it doesn’t always involve the lungs.

Disseminated TB can be difficult to diagnose. It might present without symptoms, and evidence from imaging scans can mimic other conditions. Keep reading to learn more about the symptoms, diagnosis, and treatment of disseminated TB.

Disseminated vs. miliary TB

Although some people use the terms interchangeably, disseminated and miliary TB aren’t exactly the same.

Miliary TB is a potentially life threatening form of disseminated TB that shows up with millet-seed-like spots (about 1–2 mm) on a chest X-ray.

Miliary TB accounts for about 85–90% of all disseminated TB.

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Disseminated TB is hard to detect. Someone with the condition might have the common symptoms of pulmonary TB, like a lingering cough that lasts 3 weeks or more.

But you may also experience symptoms depending on where the infection has spread. Disseminated TB can spread to your:

Symptoms may progress over days to weeks and can differ between adults and children:

Symptoms more common in adultsSymptoms more common in children
shortness of breath (dyspnea)
night sweats
abdominal pain
coughing up blood (hemoptysis)
neck stiffness
sensitivity to light (photophobia)

You may also notice raised or flat discolored areas of skin, especially with miliary TB.

Doctors may also detect different signs in children and adults:

Signs more common in adultsSigns more common in children
mental changes
pleural effusion
swollen lymph nodes (lymphadenopathy)
enlarged liver (hepatomegaly)
enlarged spleen (splenomegaly)

It’s also possible to have a TB infection without symptoms. This is called latent TB. If you have latent TB, experts still recommend treatment to prevent the development of active disease.

Doctors typically perform a tuberculin (skin) test or interferon gamma release assay (IGRA) test to determine if you have TB. However, these are often unreliable in detecting disseminated TB or distinguishing between active or latent infections.

A chest X-ray is often the first step as it may display the seed-like pattern of cells that is the hallmark of miliary TB. However, other conditions, such as sarcoidosis, can also cause that pattern. And not all disseminated TB cases show that pattern.

Other imaging tests a doctor may use include:

The only way to confirm disseminated TB is to ensure the presence of Mycobacterium tuberculosis, typically through an acid-fast smear or mycobacterial sputum stain.

Treatment for disseminated TB is a long-term course of antibiotics that includes:

  • 2 months of intensive treatment with pyrazinamide, isoniazid, rifampin, and streptomycin or ethambutol
  • 4 months of treatment with isoniazid and rifampin

Other interventions might be necessary if you’re living with another medical condition, such as HIV or AIDS, or if you develop complications during treatment. These interventions might include:

For some people, treatment might extend beyond 6 months.

Disseminated TB is a complication of TB. It occurs when a Mycobacterium tuberculosis infection spreads through your blood.

For doctors to classify TB as disseminated, it needs to affect one of the following:

  • at least two organs not next to each other
  • your blood
  • your bone marrow
  • your liver

Miliary tuberculosis is more frequent among adolescents and young adults as well as elderly persons.

Medical conditions, procedures, or medications that weaken your immune system may also raise your risk of disseminated TB. Factors linked to an increased risk include:

  • malnutrition
  • history of childhood infections
  • HIV or AIDS
  • chronic kidney disease
  • history of organ transplant
  • connective tissue disorders
  • silicosis
  • diabetes
  • cancer
  • alcohol use disorder
  • having had a recent surgery
  • recently completed pregnancy
  • tobacco use

Medications that may increase your risk of disseminated TB include:

With proper treatment, most people may recover from disseminated TB. Still, about 25–30% of people with disseminated TB die in hospital, according to a 2019 review.

Your outcome with disseminated TB may be worse if your condition has additional factors like:

  • headache, neck stiffness, and photophobia
  • liver cirrhosis
  • low or high white blood cell count
  • advancing age
  • other underlying health conditions
  • changes in mental state
  • night sweats

Here are some commonly asked questions about disseminated TB.

What is the difference between pulmonary TB and disseminated TB?

Pulmonary TB is in the lungs. Disseminated TB has moved beyond the lungs to other areas of the body.

In some cases, disseminated TB may not involve the lungs. Doctors call this “cryptic TB.” It mostly affects older adults.

How long does it take to develop disseminated TB?

It’s unclear how long it takes for disseminated TB to develop, but symptoms typically progress over days to weeks. In some cases, they can progress over months. According to a 2016 study, more than half of people with disseminated TB delay seeking medical help for over a month.

What organs are involved in disseminated TB?

A person has disseminated TB if the condition spreads through the blood to at least two organs not next to each other, the bone marrow, or the liver. Other common sites include the spleen, kidney, and adrenal glands.

Is disseminated TB contagious?

TB is a contagious disease spread through airborne bacteria. When someone with TB coughs or speaks, bacteria can enter the air, and people close to them can breathe in the bacteria.

But breathing in the bacteria does not mean you’ll develop TB. Still, you should receive treatment for the infection.

If someone with disseminated TB passes on the bacteria to another person, the other person will not necessarily develop disseminated TB, even if they develop an infection.

Is disseminated TB curable?

Disseminated TB is curable with a long course of antibiotic therapy. It is fatal without treatment.

Disseminated TB occurs when the bacteria that cause TB spread to other parts of your body through your blood. It typically starts in the lungs and moves to at least two other organs not near each other, the bone marrow, or the liver.

People with certain medical conditions, like HIV, chronic kidney disease, or diabetes, might be more likely to develop disseminated TB. Using immunosuppressive or immunomodulating medications might also raise your risk.

Doctors treat disseminated TB with at least 6 months of antibiotic therapy.