TB: A 3-Week Cough, When to Be Seen

Key takeaways

A bad cough lasting THREE WEEKS or more is the marker CDC lists among the signs of TB — not a cough that will eventually settle on its own. Many people finish several courses of cough medicine before they have a first chest X-ray.
TB speaks through a group of signs that come TOGETHER and last for weeks: a persistent cough, coughing up blood or sputum from deep in the lungs, weight loss, loss of appetite, tiredness, fever, chills, sweating at night.
Latent TB infection is DIFFERENT from TB disease. According to CDC, people with latent TB infection have no symptoms and CANNOT spread it to anyone; a positive test only means the TB bacteria are in the body, not that the person is ill yet.
Feeling well is NOT the same as being cured. According to CDC, the TB bacteria are still alive even after your symptoms have gone — stopping treatment partway can make the illness come back and can make the bacteria resistant to the very medicines being used.
TB spreads through the AIR, so ventilation matters more than any amount of cleaning. According to CDC, TB is not spread by shaking hands, sharing food or drink, sharing a toothbrush, touching bed linen, or kissing.
Anyone living with or often close to the patient needs to be tested, even with no symptoms at all — especially young children and people whose immune system is weakened.

The most important thing first: a bad cough lasting THREE WEEKS or more is the point at which a chest X-ray is needed, not a cough that will eventually settle on its own. Many people cough for a month before they have a first X-ray.

Recognising it: a persistent cough and what comes with it

According to CDC, TB bacteria usually attack the lungs but can attack any part of the body, depending on where they are growing. For TB in the lungs, the signs CDC lists are:

A BAD COUGH LASTING THREE WEEKS OR LONGER — the most notable marker of all.
Chest pain.
Coughing up blood, or coughing up sputum from deep inside the lungs.
Weakness or fatigue; weight loss; loss of appetite.
Chills; fever; SWEATING AT NIGHT — many people describe waking in the night with a wet shirt even when it is not hot.

Any single sign on its own belongs to dozens of illnesses. What makes this worrying is that they come TOGETHER and last for weeks.

TB is not only in the lungs

According to CDC, TB in the lymph nodes causes a firm red or purple swelling under the skin; in the kidney it causes blood in the urine; in the brain lining it causes headache or confusion; in the spine it causes back pain; in the larynx it causes hoarseness. Do not rule TB out just because the patient is not coughing.

What it is easily mistaken for

Easily mistaken for	What is different
Pneumonia	Worsens day by day and the breathing changes markedly; TB smoulders over weeks
Bronchitis, a cough after a cold	Usually settles over one or two weeks, with no weight loss
“A smoker's cough after all these years”	A cough that changes character, worsens, or has blood in it needs an X-ray

Latent TB infection is different from TB disease

This is where most of the misplaced fear sits. According to CDC, a person with latent TB infection has NO symptoms and CANNOT spread it to anyone — but without treatment it can turn into TB disease. According to CDC, a positive result only means that the TB bacteria are in the body; telling the two conditions apart takes further tests.

What to do straight away

Nothing at home can diagnose or treat pulmonary TB. Your part is to go to the right place, have the whole household tested as well, and then keep the course of treatment unbroken.

Go to a specialist TB service: a chest X-ray and sputum testing are what separate TB from the other causes of a cough.
Write it down: roughly when the cough began, whether there has been blood in it, how much weight has been lost, whether there are night sweats.
Cover your mouth when you cough; open the windows so the room is genuinely airy and gets sunlight. TB spreads through the AIR, so ventilation matters more than cleaning.
According to CDC, a patient who has just started treatment can still spread TB, so time off work and off school is needed — the doctor or nurse will say when going back is allowed.

What must NOT be done

Do NOT stop the medicines partway when you start feeling better, and do not take them irregularly. According to CDC, the TB bacteria are still alive even after your symptoms have gone — stopping early makes the illness worse again, and taking them wrongly makes the bacteria resistant to those same medicines.
Do NOT buy TB medicines yourself, do not reuse someone else's prescription, and do not add or drop medicines on your own. The regimen and its length are decided by the specialist.
Do NOT separate the bowls, chopsticks and toothbrushes and treat that as isolation — according to CDC, TB is not spread by sharing food, drink or a toothbrush. And do not keep the patient at a distance or out of sight: according to CDC, having TB should not stop a person living an ordinary life.
Do NOT panic if urine, saliva, tears or sweat turn orange. According to CDC, rifampin can turn body fluids orange, and that is expected and harmless — do not make it a reason to stop the medicine.

Which side effects mean calling the doctor straight away

Most side effects of TB medicines are mild. But according to CDC, if a serious side effect appears you should call the doctor or nurse IMMEDIATELY — you may be told to stop the medicine or to come back in. The serious group, according to CDC:

A rash; yellow skin or eyes; brown urine or pale stools.
Blurred vision; dizziness; abdominal pain; tingling around the mouth, or persistent numbness in the hands or feet.
A fever lasting several days; bruising easily, bleeding easily.

When you must go to hospital

GO TO EMERGENCY CARE NOW or call 115 (the emergency number in Vietnam) if: a lot of blood is being coughed up, or bright red blood by the mouthful; difficulty breathing, fast breathing, having to stop for breath mid-sentence; severe chest pain; blue lips or fingertips; a severe headache with vomiting, a stiff neck, new confusion or seizures; drowsiness, hard to wake. — BE SEEN THE SAME DAY, do not wait until tomorrow, if: the cough has lasted three weeks or more and no chest X-ray has been done; there is blood in the cough, even a little; there is clear weight loss together with night sweats; you are on TB treatment and have any of the serious side effects above; or the patient has HIV, diabetes, severe kidney disease, has just had a transplant, or is taking medicines that lower immunity. — BE SEEN EARLY, WITHIN THE NEXT ONE TO THREE DAYS, if you live with or are often close to someone just diagnosed with pulmonary TB, even with no symptoms at all. — If you are not sure, call and ask before deciding on your own.

When to call a doctor to the house

Plainly: this is an illness that has to be treated at a specialist service. Diagnosis needs a chest X-ray and sputum testing, and the regimen is decided by the specialist — nobody can do that at home.

Our part sits at the two ends. Before diagnosis: a Y Te Xanh doctor consults remotely, or comes to the house to take the history and examine the patient, and says clearly which cases must be admitted — so that you can decide to be seen early.

During treatment: a nurse comes to the house to give the medicines on time as the doctor prescribed, monitors the patient, and reports anything unusual immediately. If any sign in the box above is present, go in first and call afterwards.

The signs, the routes of transmission and the principles of taking the medicines in this article follow publicly available US CDC material on tuberculosis, and do not replace being examined. Citing CDC here does not imply that CDC endorses Y Te Xanh or our services.

Need personalised advice for your loved one? Call our hotline 094 368 81 15 (24/7) — calling to ask a question or to book costs nothing. GreenCare has doctors who come to examine, nurses who carry out doctor's orders (injections, infusions, dressing changes), remote consultation by video call, and a review of the medicines you are taking; an in-depth remote consultation, or any one after the first, is a paid service. For children we take examination and acute care only — not long-term care at home, and not newborns or expectant mothers. We confirm we have staff in your area and provide transparent pricing before we begin.

Sources

CDC — About Tuberculosis

Frequently asked questions

How is pulmonary TB transmitted, and will it spread within a household?

Through the AIR. According to CDC, TB bacteria enter the air when a person with TB of the lungs or throat coughs, speaks or sings; and a person with TB is most likely to spread it to the people they are with every day — family members, friends, co-workers or classmates. But CDC also states plainly that TB is NOT spread by shaking hands, sharing food or drink, touching bed linen or toilet seats, sharing a toothbrush, or kissing. So the things worth doing at home are to open the windows, cover the mouth when coughing, and have the whole household tested — not to set aside separate bowls and chopsticks or keep the patient at a distance.

I had BCG as a child — do I still need to worry about pulmonary TB?

You do. According to CDC, BCG is usually given to infants and small children in countries where TB is common, and it protects them from severe forms of TB such as TB meningitis — but BCG is not thought to protect people from getting TB in the lungs. One more point that often causes confusion: CDC says BCG can cause a positive skin test for TB in someone who is not infected at all, and there is no way to tell whether a positive reaction is due to BCG or to a genuine infection. So if you have had BCG and a test comes back positive, it still has to be assessed further rather than dismissed.

Does a positive TB test mean I have TB?

Not necessarily, and this is where many people worry unnecessarily. According to CDC, a positive result means that the TB bacteria are in your body; the doctor will do further tests to determine whether you have latent TB infection or TB disease — usually a chest X-ray and testing of the sputum you cough up. A person with latent TB infection has no symptoms and cannot spread it to anyone, but without treatment it can turn into TB disease, so either way a doctor has to look and decide how to proceed.

Is pulmonary TB curable, and for how long do the medicines have to be taken?

According to CDC, TB disease can almost always be treated and cured with medicine — but the medicine has to be taken exactly as the doctor or nurse instructs. Treating TB takes several medicines over several months; the exact length depends on the regimen the doctor chooses for each person, so the figure you heard from someone else may not apply to you. Ask the person treating you directly: how long is this regimen expected to run, which points require coming back for checks, and which signs mean calling straight away.

I feel completely well on TB medicines — can I stop now?

Not yet, and this is the costliest mistake in this illness. According to CDC, you will feel better after only a few weeks of treatment, but the TB bacteria are still alive in your body even after your symptoms have gone; you must keep taking the medicine until the bacteria are dead. CDC is very clear that stopping the medicine or taking it irregularly can be very dangerous: the illness will get worse again and last longer, and the bacteria may become resistant to the very medicines you are taking — at which point treatment is far more complicated and needs a TB expert. Feeling well is a signal that the medicine is working, not a signal that you may stop.

Someone in the house has just been diagnosed with TB — what should the family do?

Have everyone tested; do not wait to see who develops a cough. According to CDC, people who have been near someone with TB should be tested for TB; and young children, especially those under five, are at higher risk of progressing to TB disease once infected. Meanwhile: keep the rooms genuinely airy and sunlit, have the patient cover their mouth when coughing, and bear in mind that according to CDC a patient who has just started on medicine can still spread TB, so time off work and off school is needed — it is the doctor or nurse who will say when they may go back to ordinary life. Anyone in the house with HIV, diabetes, or taking medicines that lower immunity is the first who should be seen.

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Pulmonary TB: a three-week cough is the point for a chest X-ray, and why you must not stop treatment partway