Doctors Explain 7 Signs You Might Have Pneumonia

Distinguishing between pneumonia symptoms and symptoms of the cold, flu, or COVID-19 can be tricky. Pneumonia is a general term for an infection of the lungs usually caused by bacteria or viruses.

“It is often difficult to distinguish between upper respiratory tract infections like the common cold and lower respiratory tract infections like pneumonia in the initial stages because they frequently share overlapping symptoms, such as coughing, sore throat, and low-grade fever,” explains Raj Dasgupta, M.D., FACP, FCCP, FAASM, a pulmonary, critical care & sleep medicine physician with Huntington Health.

Meet the experts: Raj Dasgupta, M.D., FACP, FCCP, FAASM, a pulmonary, critical care & sleep medicine physician with Huntington Health; Michael Niederman, M.D., clinical director of pulmonary and critical care medicine at Weill Cornell Medical College; Norman Edelman, M.D., a pulmonologist and professor at Stony Brook University; and Jonathan Puchalski, M.D, a pulmonologist at St. Vincent’s Medical Center

While some cases of pneumonia can be severe, most are mild. Mild pneumonia, often referred to as “walking pneumonia,” is a non-severe lung infection that typically causes mild symptoms such as a dry cough, low-grade fever, and fatigue that develop gradually. Most people with walking pneumonia can continue daily activities without hospitalization, says Dr. Dasgupta.

“The best advice for managing mild pneumonia at home and avoiding hospitalization is to aggressively rest, stay strictly hydrated, and follow your healthcare provider’s treatment plan precisely. Mild pneumonia, often called “walking pneumonia,” can typically be treated with oral antibiotics (if bacterial), OTC medication for symptoms, and home care,” says Dr. Dasgupta.

Here’s how to tell if it’s pneumonia or another type of infection.

“Pneumonia is an infection in the gas-exchanging units of the lung (called the alveoli),” says Michael Niederman, M.D., clinical director of pulmonary and critical care medicine at Weill Cornell Medical College in New York. Translation: the air sacs in your lungs become inflamed or even fill with fluid or pus, which interferes with your body’s ability to deliver oxygen to your blood.

“About half the time, it’s due to bacteria,” says Norman Edelman, M.D., a pulmonologist and professor at Stony Brook University. “The other half the time, it’s due to viruses.” The most common type of pneumonia is caused by the bacteria streptococcus pneumoniae, in the same family of bacteria that causes strep throat. Influenza is also a key virus that can spur pneumonia, and fungi can be a culprit, too. The novel coronavirus, of course, can also cause pneumonia, albeit one with a longer incubation period than, say, the flu, says Dr. Dasgupta. He notes that bacterial pneumonia typically starts suddenly with a high fever and thick, colored mucus, while viral pneumonia usually develops gradually with milder symptoms, a dry cough, and clearer mucus.

“Pneumonia develops if the organism overwhelms the patient’s host defenses,” says Dr. Niederman. This basically means that a foreign bug takes over your immune system, even if you’re generally healthy. That’s because certain organisms, like those associated with the flu, can be particularly hostile or invade your body in large numbers.

Pneumonia can be contracted in tons of different ways, from inhalation of fumes to living in a moldy building. Overall, it’s divided into two different categories: community-acquired pneumonia and hospital-acquired pneumonia, says Dr. Edelman.

Community-acquired pneumonia can be acquired anywhere, anytime. Bacterial and viral pneumonia are contagious, so you can pick it up from someone’s stray cough or sneeze, by sharing cups, or not washing your hands as often as you should.

Then there is hospital-acquired pneumonia, which is the kind you pick up while staying in the hospital or at a chronic care facility, like a nursing home or rehab center. “We make that distinction because the bugs that cause these two types of pneumonia tend to be different and treated differently,” says Dr. Edelman.

When your immune system is compromised due to viral respiratory infections, such as influenza or RSV, this significantly increases the risk of secondary bacterial infections by damaging the airway lining, impairing immune responses, and allowing bacteria to adhere to cells. This “superinfection” can cause severe pneumonia and worsening symptoms, says Dr. Dasgupta.

Dr. Dasgupta also notes that COVID-19 can also lead to acute respiratory distress syndrome, or ARDS, which is a life-threatening lung injury that allows fluid to leak into the lungs. Because breathing becomes difficult and oxygen cannot get into the body, a patient is often placed on a ventilator. ARDS and pneumonia are closely related in critically ill patients.

Pneumonia can look a lot like the common cold from the outside. Amongst its most common symptoms are:

• Coughing
• Shortness of breath
• Chest pain during breathing or coughing
• Increased phlegm that’s green, grey, or yellow in color
• Fever
• Nausea, vomiting, or diarrhea
• Fatigue

But “the common cold will usually have other symptoms that pneumonia won’t, like a sore throat or runny nose,” says Connecticut-based pulmonologist Jonathan Puchalski, M.D. Those symptoms—along with the cough or fever you might be experiencing—will usually go away pretty quickly.

With pneumonia, on the other hand, they’ll either remain consistent or become more severe. “We all get colds and coughs,” says Dr. Edelman. “If it seems like an ordinary cold and there’s a cough associated with it and you’re otherwise not sick, I think you can wait a week before you see your doctor. If it gets worse, see your doctor immediately.”

“Getting worse” could include symptoms like high fevers, bad headaches, and severe chest pain, says Dr. Edelman, which could imply a more serious bacterial pneumonia. If that’s the case, you should head to the doctor’s office ASAP. The same goes if you believe you have COVID-19, and your symptoms get noticeably worse. “When you have chest pain and you can’t breathe and you know something’s really not right, the best place to be is in a monitored hospital setting,” says Dr. Dasgupta.

The type of pneumonia you have will determine what kind of treatment you’ll get.

💊 If you have a viral infection…

“If it’s viral, it usually takes care of itself,” says Dr. Edelman. Unfortunately, it could take your body up to a month to really get rid of the viral infection, so in the meantime, doctors will often try to control the symptoms you’re experiencing, like a fever, as opposed to the virus itself, says Dr. Puchalski.

Leaving it untreated might cause you some discomfort by not controlling the symptoms, but the infection itself will still more than likely go away.

💊 If you have a bacterial infection…

With bacterial pneumonia, prescription treatment becomes super important. For community-acquired pneumonia, your doctor will usually prescribe you an antibiotic, and the infection should be gone in a week to 10 days, says Dr. Edelman.

If it’s hospital acquired, it might require some more intensive medication. “If you have hospital-acquired pneumonia, that’s usually a bug that’s resistant to the ordinary drug your doctor might use for community-acquired pneumonia,” says Dr. Edelman. “You usually get several antibiotics to try and cover all the possible resistant organisms that could be causing pneumonia.”

If you leave bacterial pneumonia untreated, however, you could be putting yourself at serious risk. “If it’s bacterial, then you worry about it spreading to other parts of the lung or other parts of the body,” says Dr. Edelman. “It can go to your heart, it can go to your brain, it can go all kinds of places.”

The worst-case scenario? The infection could move out of the lungs and cause sepsis, an intense immune system reaction that can be fatal. In fact, pneumonia is the leading cause of death from infectious diseases, says Dr. Niederman. It can also cause ARDS.

The bottom line? Check in with your doctor as soon start experiencing symptoms of pneumonia, especially if those symptoms start getting worse.

Even better than treatment is prevention, which comes in the form of immunization, says Dr. Niederman. Make sure you get your flu shot every year, and if you’re someone suffering from chronic illness or you’re over the age of 65, ask your doctor about the pneumococcal vaccine, which protects your body against the streptococcus bacteria.

Common health advice that people follow to prevent the spread of many viral infections also works for pneumonia: Wearing a mask, washing your hands regularly (use soap and scrub for at least 20 seconds, and use hand sanitizer if you can’t!), disinfecting your phone and counters, finding time to unwind from the day’s stress, getting plenty of sleep, and eating a healthy diet full of immunity-supporting foods all work toward keeping malicious bugs out of your system.

Raj Dasgupta, M.D. is an ABIM quadruple board-certified physician specializing in internal medicine, pulmonology, critical care, and sleep medicine. He practices at the University of Southern California, where he is an associate professor of clinical medicine, assistant program director of the Internal Medicine Residency Program, and the associate program director of the Sleep Medicine Fellowship. Dr. Dasgupta is an active clinical researcher and has been teaching around the world for more than 20 years.