Tuberculosis is a common disease that spreads easily in crowded conditions. While it is more common in third world countries where sanitation is poor, it can also be found in the first world. This disease is caused by mycobacterium tuberculosis. It can spread through the air and infect the lungs. Once someone contracts the disease, it can lay dormant in their body for years before any physical symptoms appear. Often, symptoms of tuberculosis will develop after your immune system has weakened. You may develop symptoms like a fever, night sweats, coughing or weight loss.
Tuberculosis (TB) is a serious infection that requires professional medical treatment. If you believe that you were exposed to TB, it is important that you go to your doctor to get a TB test. Once you are tested, you may wonder, “What does a positive TB test look like?”. The following descriptions will cover what to expect after you are given a TB test.
What Does a Positive TB Test Look Like?
When you are tested for TB, your doctor will inject a purified protein derivative (PPD) into your arm. Afterward, you have to wait for several days to see if there is a reaction. It is normal to have slight inflammation, and the size of the bump that develops will help determine if you have tuberculosis.
If you have a reaction of 15 mm or more, it is considered a positive test no matter what your background is. If you are in the high risk category for contracting this infection, then only a 5 mm reaction is considered enough for a positive test. Certain immigrants, drug users and children only need a 10 mm reaction to be positive for TB.
If you have received a positive result, your health care provider will most likely recommend a chest x-ray. This is done to see if tuberculosis is already active in your lungs or if it is just dormant in your body. Once your doctor knows the severity of your condition, they will be able to decide the best course of treatment.
For an active infection, you will be given treatment to help get rid of the disease. If the infection is just dormant, the main goal will be to prevent the infection from becoming active.
Figuring Out the Results of a TB Test
After the test, the way your skin reacts to the PPD will determine if you have TB or not. If the area is only slightly inflamed or swollen, then your test is most likely negative. If you receive a slight reaction of 5 mm about 48 to 72 hours after taking the test, then you may have a positive result if you are a high risk patient. High risk patients are those who have a weakened immune system or who have been in close contact with someone who has TB. This group also includes people with HIV or transplanted organs.
A 10 mm result is considered positive if you are a drug user or an immigrant from a country that has TB. It is also considered positive if you have an illness like kidney failure or diabetes. Individuals who were in a high-risk environment may be considered positive at this level. Likewise, infants who were exposed to health care workers or other adults who have TB only need a 10 mm result to be positive for TB.
Anyone who does not fit in the previous groups is considered positive if they have a 15 mm reaction. While there are occasions when someone may get a false positive or a false negative, the test is generally quite accurate. Certain steroids, vaccines and medical treatments can affect the results at time.
What Are the Symptoms of TB?
If you are already experiencing symptoms of having tuberculosis, then it is more likely that you could get a positive result. Keep in mind that inactive TB will not have any symptoms. Only active TB will cause symptoms in your body. If you do have symptoms, you may experience fatigue, excessive sweating, continuous coughing, a constant fever or chest pain. You may also cough up blood.
Keep in mind that these symptoms could also be caused by another illness. While it could be caused by something else, it is important to get tested for TB if you exhibit these symptoms. A TB test is the only way to find out for sure if tuberculosis is responsible for your symptoms.
Preparing for Your TB Test
Your doctor will most likely go over the ways that you can prepare for your TB test beforehand. It is important that you tell your doctor about any medications, steroids, vaccines or medical problems in advance since these could affect the accuracy of your TB test and could even make a false positive result.