“True” Chronic SOB is always felt on exertion. Patients feel well at rest, with normal vital signs and normal oxygen saturation tests (if not, see Life-Threatening Acute SOB). For a patient without any clues in the medical history (like having had a heart attack in the past), clinicians think as follows:
Causes of Chronic Shortness of Breath
• Heart Failure (HF) **
• Angina **
• Deconditioning (out-of-shape) **
** SOB, with exertion, may come and go
• Asthma **
• COPD (esp. Emphysema)
• Interstitial Lung Disease
Click for List of Rare Causes
1. Decide if Angina (Coronary Artery Disease) is a possibility, by factors below. If so, work up with EKG & stress tests [see Diagnosing Coronary Artery Disease].
- Duration: SOB on exertion, lasts approx. 1-5 min upon resting (never just seconds)
- Risk Factors: Hypertension, Smoking, Diabetes, High Cholesterol, Cocaine / Meth, Family History of heart attack (at around patient’s age)
- Chest Pain occurring along with the SOB, described as “pressure,” “heaviness,” squeezing,” or “tightness,” maybe in Left shoulder, upper arm, neck, or lower jaw.
- Other Symptoms occurring along with the SOB — a) Nausea/Vomit; b) Lightheadedness; c) Cold Sweat breaks out on forehead
- Beware that a person who has waited out Angina may be on the verge of a full-fledged Heart Attack (M.I.) (see Acute SOB)
2. But let’s assume Angina is not a consideration. We focus on the Exam by Stethoscope:
** Bibasilar rales (crackles) at bottom of both Lungs, with normal inspiratory-to-expiratory phases, suggests Heart Failure (HF), especially in the older patient. Swollen feet / neck veins clinches it. See Lung Sounds)
- For HF → order blood tests for a BNP & Complete Blood Count (CBC), also an Echocardiogram
** Abnormal Heart Exam — may suggest Heart Failure due to heart disease (damaged valve, abnormal rhythm like Atrial Fibrillation, etc).
- Order EKG and Echocardiogram; treat / refer to Cardiology (or treat A. Fib.), etc.
** Wheezes in Lungs, or expiration longer than inspiration (see Lung Sounds) suggests Asthma or COPD
- If non-smoker, it’ll certainly be Asthma, especially if they also cough.
- If long smoking history, bet on COPD (Chronic Bronchitis if also a cough, Emphysema if no cough).
- If Asthma / Chronic Bronchitis seem likely, we give a trial of treatment.
- Can also check Peak Flow, give an asthma treatment, & see if Peak flow improves. If so, we have a diagnosis.
3. If none of above, or if symptoms remain unchanged after an Asthma treatment trial, we order:
- Chest X-Ray (CXR)
- Complete Blood Count (CBC), especially for Anemia (low hemoglobin).
- BNP (blood test) if Heart Failure is a possibility (EKG too)
- Comprehensive Metabolic Panel (basic blood tests) and thyroid tests, if we can’t completely distinguish “fatigue” vs. “SOB” (see also our symptom topic Fatigue)
- Check the Oxygen Saturation during exertion (see link). If it drops, there’s definitely something wrong (see 4 & 5 below for possible tests)
4. Everything Normal, No Diagnosis? And we’re convinced the patient experiences “true” SOB? We order:
- Echocardiogram — to see if something’s wrong with the heart
- Pulmonary Function Tests (PFTs) — to see how the lungs are working
5. Heart or Lung abnormalities found by the above tests? Next Steps:
- For Heart: Cardiology referral, for maybe Cardiac Catheterization (right and/or left sides)
- For Lung: Chest CT Scan (regular, or high-resolution); maybe “V/Q Scan” for the rare case of Chronic Pulmonary Embolism; referral to Pulmonologist
6. Still No Abnormalities (everything normal)? We can certainly reassure the patient. Might just be simple Deconditioning.
- We keep following them to make sure nothing changes, & that they’re not losing weight.
- If getting worse, repeat some of the above tests, maybe refer to a Pulmonologist
See Chronic Shortness of Breath — Full Text for more in-depth explanations and discussions.