Upper respiratory conditions don’t cause “true” Shortness of Breath (SOB), which by definition always feels worse with exertion (not just a sensation of SOB while coughing, or from a stuffy nose). So anyone with Cough and also true SOB has to have some sort of lung, or rarely heart, disease. If there’s no fever, it’s very unlikely to be pneumonia or other infection; except of course…
Covid-19 – that’s the first thing we think of nowadays when someone has a cough, especially if they also feel short of breath. Covid often has a fever, but not necessarily. We’re tempted to just send them for a Covid test, but we can’t refuse to evaluate them if there’s also SOB. We can send them to an ER if we’re not otherwise equipped to isolate, but we can’t send them home without a diagnosis.
They need to be examined, because diseases causing SOB can be fatal. Most lung diseases that cause an acute cough can be diagnosed by abnormal lung sounds that are heard with a stethoscope. Usually, it’s because of Bronchospasm. The rest of this discussion addresses conditions we focused on before Covid, and which still need due consideration because they’re still just as common as always.
Bronchospasm is when the bronchi are narrowed by either constriction of bronchial muscle, and/or swelling / mucus inside. See Lower Respiratory Tract, Diagram D (Asthma / Bronchospasm) for a picture-worth-a-whole-bunch-of-words. How does bronchospasm sound through a stethoscope?
- Wheezes (long, high-pitched sounds during expiration)
- Rhonchi (squeaks / gurgles, during inspiration or expiration)
- Long Expiratory Phase
Problem! Clinicians all know that wheezes mean bronchospasm. But some don’t realize that rhonchi do also. And quite a number fail to appreciate that bronchospasm may declare itself with “clear lungs,” but a long expiratory phase. Think of how we sound when we breathe normally: a brief breath in, then exhale, and pause before the next breath.
This “exhale + pause” looks longer than the breath in, when simply watching someone from the outside. But listening on the inside with a stethoscope, it’s the opposite: inspiration normally sounds longer than expiration, because the pause sounds silent. However, with bronchospasm, we hear the high-pitched wheeze of struggled expiration all through the pause; if the pitch is too high, we can’t hear the sound itself, just the time that it occupies (unless we’re a dog).
If you ever get seen for a cough, and your provider tells you, “The lungs are clear,” be sure to ask, “Does inspiration sound longer than expiration?” If not, it’s bronchospasm, due either to acute bronchitis, asthma, or chronic bronchitis.
What are these diseases, which cause cough plus SOB but no fever, and how do we distinguish among them?
Acute Bronchitis — A viral infection of the lung, for which there’s no treatment, but which gets better on its own. Problem is, lots of health care providers hear the suffix “–itis,” think of “infection,” and prescribe antibiotics. Useless for viruses. But the normal bacteria in our throats eventually wind up resistant to them, so if we ever get a real pneumonia, drugs might not work.
With a stethoscope, Acute Bronchitis sounds just like asthma. Actually, common asthma “rescue” inhalers work just fine for it (see Asthma Medications). Sometimes the virus produces enough inflammation that bronchospasm lasts onward 2-3 months, even though the virus is dead & gone. In that case, additional anti-asthma “controller” medications are quite useful. The difference is that however long the bronchospasm from bronchitis may last, when it’s gone, it’s over. Asthma, however, will keep recurring.
Thus, another common clinical mistake. Viral bronchitis shouldn’t occur more than once a year at the most, and usually just once or twice a lifetime. Anybody who gets repeated bouts of “bronchitis” really has asthma. They need a solid diagnosis and proper treatment, with both “rescue” and “controller” medications. The last thing they need are repeated courses of antibiotics.
Asthma — Caused by something in the air that triggers bronchospasm in a susceptible person. It can be something allergic (like pollen) or irritative (smoke, chemicals, etc.). Asthma’s main symptom is a cough, but depending on how bad the bronchospasm is, often shortness of breath as well. The latter is what makes asthma serious, even, on rare occasions, fatal.
Shortness of breath is significant when a person can’t tolerate normal activities, like walking up stairs. When present at rest, it’s real serious (go to an ER). If even worse, a person can’t concentrate, may become confused or agitated. And most ominous of all is when the inability to breathe makes an asthmatic drowsy. Soon they’ll just stop. Either of the last two situations, call 911. Anyone who looks bluish around the lips or face — also call 911.
When a person has a new cough, I never diagnose asthma on the first visit, no matter what I hear in the lungs. Like we said, viral bronchitis sounds exactly the same. So that’s what I call it, even if treatment is the same, because I’m reluctant to apply a lifetime label. But after the second or third episode, it’s an injustice to not make the diagnosis and treat as appropriate.
Chronic Bronchitis — This is a form of Chronic Obstructive Pulmonary Disease (COPD), which primarily affects smokers & farmers. It’s technically defined as cough with sputum (phlegm) every day for at least three months, two or more years in a row.
A person with COPD can experience an “acute exacerbation,” which shows itself as bronchospasm. It’s treated similarly to asthma, though the preferred medications are a little different. Sometimes the exacerbation includes a change in normal sputum, from frothy-clear to thick-green. In the latter case, bacteria are growing too much, so antibiotics help.
Heart Failure — This causes cough and SOB, but usually without bronchospasm (wheezes may be heard in rare cases). There’s no chest pain; it’s not the same as “Heart Attack“. It’s sometimes called “Congestive Heart Failure (CHF)”.
If the heart doesn’t pump strongly enough, blood backs up in the lungs, where fluid leaks out. This mainly causes shortness of breath on exertion, but can also cause a cough, especially while lying down. Patients with Heart Failure may wake up suddenly gasping, and commonly have to sleep propped up with pillows (so the excess fluid sinks to the bottom of the lungs, instead of flooding them).
Who gets Heart Failure? People with weak hearts due to:
- Previous Heart Attack
- Long-standing Hypertension (high blood pressure)
- Damaged heart valves
- Atrial Fibrillation
- Hyperthyroidism (untreated)
- Myocarditis (heart infection)
How do we diagnose Heart Failure? We discuss it at length in our topic Shortness of Breath. There are various physical signs, like rales at the bottoms of both lungs (crackles heard with a stethoscope), and swollen feet or neck veins, as well as a blood test and echocardiogram.
The point here is that a person with new cough, especially lying down at night, and also shortness of breath while walking, may have heart failure instead of lung disease. Clinicians all realize this when caring for older persons, or those with known heart problems. But I’ve seen them miss the rare viral Myocarditis which young people can get.
A young person with cough, true SOB, and no fever probably has acute bronchitis or asthma. But if there are no clear signs of bronchospasm on lung examination, they should have a chest x-ray & other tests for the heart.
And the patient with Cough plus SOB but Normal Lung Sounds? If they really have true SOB, there’s something wrong with the lungs or heart (or Anemia, or rare diseases of the trachea). They need a chest X-Ray for sure. If it’s normal, & lung sounds are really normal, I’d bet on Asthma if the cough were prominent (see also discussion of Asthma under topic Chronic Cough). If the SOB is more impressive than cough, I’d go to our thought-process for Shortness of Breath.
A brief note in conclusion: SOB is serious; our bodies have to breathe well. We can live fine with a cough, but not without oxygen. Even if “cough” is your main symptom, never let a medical provider send you home with “cough syrup” if you also have true SOB. Make them diagnosis a disease that includes the SOB, and give you adequate treatment for it. And even if your oxygen level seems normal, if you’re feeling true SOB, have them recheck the oxygen after you exercise (brisk 6-minute walk is standard). And make them explain why, with SOB, this is not something serious, since we never give cough syrup to someone with a serious lung condition.
See also Acute Cough for the clinician’s condensed thought-process when face-to-face with a patient.