Fever and cough, now with chest pain when you breathe in: what do pneumonia tests check in adults?

Hello. I am Shunichi Gamo, MD, PhD, a board-certified pulmonologist and the director of Sendai International Airport North Clinic.

When a fever and cough go on and your chest starts to hurt when you breathe in, it is natural to worry that it might be pneumonia. However, symptoms alone cannot tell whether you have pneumonia. Doctors find out by combining an examination with imaging tests.

This article explains what doctors check when pneumonia is suspected in an adult, whether everyone needs the same tests, and how long recovery takes after treatment. It also covers when to see a doctor and what it helps to tell them at your visit.

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Do fever, cough and chest pain mean pneumonia? What symptoms does pneumonia cause?

In adults, clues to pneumonia include cough, shortness of breath, chest pain when breathing in, sweating, fever or chills, and body aches. For adult outpatients with a sudden cough and suspected pneumonia, a US expert panel lists these symptoms as suggesting pneumonia. [1]

The same report also lists other findings that suggest pneumonia: a temperature of 38°C or higher, fast breathing, and a new abnormal sound in one limited area when the doctor listens to the chest. [1]

Still, these are only “clues that raise suspicion.” Checking whether you have all of these symptoms is not enough, on its own, to tell whether you have pneumonia.

When you see a doctor, bring written notes on when the fever, cough and chest pain each began. Also note whether the pain changes when you breathe deeply or change position.

With fever and cough, can symptoms alone tell a cold from pneumonia?

Symptoms alone cannot clearly tell a cold from pneumonia. A systematic review (a method that gathers and analyzes many studies) looked at adult outpatients. It found that people with an acute respiratory infection were very unlikely to have pneumonia if their chest examination and measurements such as temperature, breathing rate and pulse were all normal. [2]

This review found that in a group where the chance of pneumonia was estimated at 4% to begin with, the chance that such a person had pneumonia was 0.4%. [2]

Put the other way around, if the measurements or the examination are abnormal, it becomes worthwhile to check further, including with imaging tests.

What is checked	What studies of adult outpatients have found
Temperature, breathing rate and pulse are normal, and the chest sounds are normal too	In adults seen for an acute respiratory infection, pneumonia is very unlikely. [2]
The measurements or the examination are abnormal	When pneumonia is suspected in adult outpatients, a chest X-ray is suggested to check for it. [1]

If your fever continues, your cough gets worse, or it hurts when you breathe in, see a doctor soon.

When fever and cough suggest pneumonia, what do the examination and chest X-ray check?

During the examination, the doctor measures things such as your temperature, breathing rate and pulse, and listens to your chest to check for signs that suggest pneumonia.

For adult outpatients with suspected pneumonia, a chest X-ray is suggested to make the diagnosis more accurate. [1]

A chest X-ray checks whether the lungs show a shadow that points to inflammation. The doctor interprets the image together with your symptoms and examination findings.

This report on outpatient care says that measuring CRP (a blood test value that shows how strong the inflammation in the body is) helps both to diagnose pneumonia and to rule it out. On the other hand, measuring procalcitonin (a blood test value that tends to rise with bacterial infections) gave no added benefit in this setting. [1]

These are suggestions from US experts, and the way testing is done differs by country and by medical facility.

After your tests, ask the doctor what the images showed and how much of the cause of your chest pain has been explained.

When fever and cough suggest pneumonia, does everyone need a CT scan or a culture test?

Not everyone with suspected pneumonia gets a CT scan (an X-ray test that takes cross-section pictures of the body). The same goes for a culture test (a test that grows germs to identify their type) to look for the germ causing the illness in phlegm or other samples. For adult outpatients with a sudden cough and suspected pneumonia, a US expert panel suggests that routine microbiology tests are not needed. [1]

Two studies looked at CT scans in adults with suspected pneumonia who came to the emergency department or were admitted to the hospital. When a chest X-ray alone was unclear, CT helped doctors reconsider the diagnosis of pneumonia. It was especially useful for confirming that a person did not have pneumonia. [3]

These results come from adults in the emergency department or the hospital. They do not mean that CT is recommended for every outpatient. CT changes the diagnosis in a certain share of people. However, whether it is cost-effective and whether it improves how treatment goes still need to be studied. [3]

Test	Role shown in the research (who was studied)
Chest X-ray	Suggested for adult outpatients with suspected pneumonia to make the diagnosis more accurate. [1]
CRP measurement	In adult outpatients, measuring CRP is described as helping both to diagnose pneumonia and to rule it out. [1]
Microbiology tests	For adult outpatients, it is suggested that microbiology tests do not need to be done routinely. [1]
CT	In studies of adults in the emergency department or the hospital, CT is described as reducing overdiagnosis of pneumonia and making other diagnoses easier to find. [3]

If an extra test is recommended, try asking what the test is meant to check.

If fever and cough suggest pneumonia, when are antibiotics needed?

Antibacterial drugs (commonly called antibiotics) are suggested when pneumonia is suspected in a setting where imaging tests are not available, following local or national guidelines. [1]

US medical societies have also issued a guideline on how to treat community-acquired pneumonia (pneumonia that starts outside the hospital) in adults. Its topics include how to decide where care should take place and how to choose the first antibiotic. [4]

The American Thoracic Society’s updated guideline covers diagnosis with lung ultrasound, antibiotics when a respiratory virus test is positive, how long to give antibiotics, and the use of steroids. [5]

Which medicine is used, and for how long, depends on things such as how severe your symptoms are and any long-term conditions you have. For the dose and the number of days, follow what the prescribing doctor or the pharmacist tells you.

Do not change the dose or stop your prescribed medicine partway through on your own. If you have questions, ask the clinic or hospital that prescribed it.

After the fever from pneumonia goes down, can the cough and tiredness linger?

Even after the fever from pneumonia goes down, cough and tiredness can continue. One study looked at 134 adults diagnosed with pneumonia in the emergency department of Massachusetts General Hospital (people predicted at diagnosis to have a low risk of death). Counting from the time of diagnosis, the median time for the fever to go away was 3 days. For the cough and the tiredness, the median time was 14 days each. [6]

In this study, 35% of people still had some symptoms at the end of the 28-day follow-up period. [6]

A study involving several hospitals and other facilities looked at 576 adults diagnosed with pneumonia (people judged to have a low risk of death). Thirty days after diagnosis, many people still had symptoms other than chest pain when breathing in. At 90 days, cough, tiredness and other symptoms were still about twice as common as before the pneumonia. [7]

Another study followed people after they finished their antibiotics. Of 535 adults with pneumonia who came to hospital emergency departments, 64% still reported at least one pneumonia-related symptom 6 weeks after finishing treatment. [8]

In this study, being younger was linked to symptoms going away completely. So was not having asthma or chronic obstructive pulmonary disease (a disease in which air has trouble flowing through the lungs, caused by things such as many years of smoking). [8]

These studies are older reports, and each one started counting time from a different point. To know what to expect for your own recovery, please get examined and ask your doctor.

Study	What was found (who was studied and when counting started)
134 adults diagnosed with pneumonia in the emergency department (people predicted at diagnosis to have a low risk of death)	Counting from diagnosis, the median time for the fever to go away was 3 days, and for the cough and the tiredness it was 14 days. [6]
576 adults with pneumonia judged to have a low risk of death	Thirty days after diagnosis, many people still had symptoms other than chest pain when breathing in. [7]
535 adults with pneumonia who came to the emergency department	Six weeks after finishing antibiotics, 64% reported one or more symptoms. [8]

If your cough or tiredness drags on, don’t just put up with it. Tell your doctor which symptoms you have and how long they have lasted.

With fever, cough and chest pain, when should you seek medical care right away?

If you suddenly have severe trouble breathing, or you are so short of breath that you cannot finish a sentence, do not wait and see. Go to the emergency department. The same applies if your lips change color or you become confused or drowsy.

Other sudden changes are also signs that you should be seen in the emergency department. These include coughing up a large amount of blood, chest pain that suddenly gets worse, or breaking out in a cold sweat.

Even after you have been diagnosed with pneumonia, the diagnosis or treatment may need to be reviewed if your fever, chest pain or breathlessness gets worse while you are taking your medicine. Even if you have not finished treatment, see your doctor again soon.

If you have severe trouble breathing or are coughing up a large amount of blood (hemoptysis), go to the emergency department right away.

At a follow-up visit for pneumonia, what should you tell the doctor?

At a follow-up visit for pneumonia, describe in detail how your fever, cough and chest pain have changed since treatment began. Whether your symptoms have improved, stayed the same or gotten worse since the first visit gives clues for reviewing the diagnosis.

Your smoking habits, long-term conditions and age also help the doctor plan testing and think about your expected recovery. Please also feel free to mention changes that may not seem related, such as skin symptoms or other health problems.

When test results are explained to you, it is reassuring to check two things. Ask whether any part of the cause is still unclear, and when you should see the doctor again if your symptoms continue.

What to tell the doctor	Why it matters
How your fever, cough and chest pain have changed since treatment began	It gives clues for reviewing the diagnosis and treatment.
Smoking habits, long-term conditions and age	They help in planning testing and thinking about your expected recovery.
Skin symptoms or other health problems	They help the doctor who examines you see the whole picture.
How long your cough or tiredness has lasted	It helps show whether recovery is simply taking longer or there is another problem.

Before your follow-up visit, write a short note on how your symptoms have changed. That way you can get the key points across even in a short visit.

Summary

• Cough, chest pain when breathing in, and fever are clues that suggest pneumonia, but symptoms alone cannot confirm it.
• For outpatients, a chest X-ray is suggested to check for pneumonia when the examination points to it. Not everyone needs a CT scan or a culture test.
• The type of antibiotic and the number of days depend on things such as how severe your symptoms are. Follow what the prescribing doctor or the pharmacist tells you.
• Cough and tiredness can last for several weeks after the fever goes down. If you have severe trouble breathing or are coughing up a large amount of blood, you need to go to the emergency department right away.

Frequently asked questions

If chest pain comes on top of a fever and cough, is it always pneumonia?

Not necessarily. Cough, fever and chest pain when breathing in are clues that suggest pneumonia, but symptoms alone cannot confirm it. Doctors find out by combining an examination with tests such as a chest X-ray when needed.

If pneumonia is suspected, will I always have a CT scan too?

For adult outpatients with suspected pneumonia, a chest X-ray is suggested to check for it. [1] In studies of adults in the emergency department or the hospital, CT is described as helping doctors reconsider the diagnosis. [3] At your visit, ask the doctor whether extra tests are needed and what they are for.

Once the fever from pneumonia goes down, can I assume I have recovered?

Cough and tiredness can last for several weeks. In a study of 134 adults diagnosed with pneumonia in the emergency department (people predicted at diagnosis to have a low risk of death), 35% still had some symptoms 28 days after diagnosis. [6] However, if your symptoms get worse or you have severe trouble breathing, see a doctor soon.

What should I do if my fever or chest pain continues even though I am taking antibiotics?

Do not stop the medicine or change the dose on your own. See your doctor again soon. If the illness does not respond to treatment, the diagnosis or treatment may need to be reviewed. For the type of medicine and the number of days, follow what the prescribing doctor tells you.

Disclaimer

This article provides general medical information. It does not replace an examination, diagnosis or treatment by a doctor. The content is based on medical knowledge at the time of publication, but the right approach differs with each patient’s condition and background.

If you are worried about your symptoms, please talk to your regular doctor or a specialist medical facility.

References

1. Hill AT, Gold PM, El Solh AA, Metlay JP, Ireland B, Irwin RS, et al. “Adult Outpatients With Acute Cough Due to Suspected Pneumonia or Influenza: CHEST Guideline and Expert Panel Report.” Chest, 2019 Jan; 155(1): 155-167. DOI: 10.1016/j.chest.2018.09.016 PMID: 30296418
2. Marchello CS, Ebell MH, Dale AP, Harvill ET, Shen Y, Whalen CC. “Signs and Symptoms That Rule out Community-Acquired Pneumonia in Outpatient Adults: A Systematic Review and Meta-Analysis.” J Am Board Fam Med, 2019; 32(2): 234-247. DOI: 10.3122/jabfm.2019.02.180219 PMID: 30850460
3. Garin N, Marti C, Scheffler M, Stirnemann J, Prendki V. “Computed tomography scan contribution to the diagnosis of community-acquired pneumonia.” Curr Opin Pulm Med, 2019 May; 25(3): 242-248. DOI: 10.1097/MCP.0000000000000567 PMID: 30730311
4. Metlay JP, Waterer GW, Long AC, Anzueto A, Brozek J, Crothers K, et al. “Diagnosis and Treatment of Adults with Community-acquired Pneumonia. An Official Clinical Practice Guideline of the American Thoracic Society and Infectious Diseases Society of America.” Am J Respir Crit Care Med, 2019 Oct 01; 200(7): e45-e67. DOI: 10.1164/rccm.201908-1581ST PMID: 31573350
5. Jones BE, Ramirez JA, Oren E, Soni NJ, Sullivan LR, Restrepo MI, et al. “Diagnosis and Management of Community-acquired Pneumonia: An Official American Thoracic Society Clinical Practice Guideline.” Am J Respir Crit Care Med, 2026 Jan 01; 212(1): 24-44. DOI: 10.1164/rccm.202507-1692ST PMID: 40679934
6. Metlay JP, Atlas SJ, Borowsky LH, Singer DE. “Time course of symptom resolution in patients with community-acquired pneumonia.” Respir Med, 1998 Sep; 92(9): 1137-42. DOI: 10.1016/s0954-6111(98)90408-5 PMID: 9926169
7. Metlay JP, Fine MJ, Schulz R, Marrie TJ, Coley CM, Kapoor WN, et al. “Measuring symptomatic and functional recovery in patients with community-acquired pneumonia.” J Gen Intern Med, 1997 Jul; 12(7): 423-30. DOI: 10.1046/j.1525-1497.1997.00074.x PMID: 9229281
8. Marrie TJ, Lau CY, Wheeler SL, Wong CJ, Feagan BG. “Predictors of symptom resolution in patients with community-acquired pneumonia.” Clin Infect Dis, 2000 Dec; 31(6): 1362-7. DOI: 10.1086/317495 PMID: 11096003