It may start with a cold or flu-like infection that leaves you feeling run-down and achy, says Neil Kalsi, M.D., an assistant professor in the University of Nebraska Medical Center Department of Family Medicine. And with untreated bacterial bronchitis, the infection may worsen, particularly in patients with underlying lung diseases, and the airways leading to the lungs may get further inflamed and filled with mucus. The result can be a nagging cough, which may be wet or dry, that can persist for weeks. Other symptoms can include sore throat and soreness in the chest from coughing.

Since bronchitis is frequently caused by a virus, doctors defer prescribing antibiotics unless a bacterial infection sets in. Instead, helpful tips for feeling better include a cozy blanket, plenty of rest and fluids—especially hot beverages—and that popular home remedy, honey, which may provide temporary relief.

Recovery can take time. “It may not be a day-by-day improvement, but rather a week-by-week improvement,” Kalsi says.

While bronchitis affects the larger airways, pneumonia develops in the air sacs of the lungs. It creates inflammation and fluid buildup. And it can be far more dangerous: Pneumonia causes more than 1 million hospitalizations and more than 50,000 deaths each year in the U.S., according to the American Lung Association.

Influenza, RSV, COVID-19 and the common cold virus can all lead to pneumonia. But so too can a common type of bacteria, pneumococcus, which can be spread by coughing, sneezing or touching infected surfaces. Pneumonia can trigger a bad cough as well as other, more serious symptoms, and can include:

Chest X-rays, ultrasound, CT scans and other techniques may be used to diagnose pneumonia. A second test is sometimes used to confirm the diagnosis.

Treatment depends on what’s causing the infection—a diagnosis your doctor may make using blood, sputum or urine tests. If it’s bacterial pneumonia, your doctor may prescribe an antibiotic. And in rare cases when pneumonia is caused by a fungal infection, antifungals can help alleviate the illness.

Viral pneumonia, on the other hand, isn’t treated with antibiotics. Some prescription medications can help with the symptoms of viral pneumonia.

A fever that’s higher than 101 degrees is a sign you need to see a doctor, says Anthony Szema, M.D., who specializes in pulmonary diseases and clinical immunology at Hofstra/Northwell on Long Island, New York. The same goes if you have chest tightness or feel short of breath, very fatigued or dehydrated.

Let your doctor know what OTC medications you’re taking and ask what changes in your symptoms require a follow-up. Unless you’re diagnosed with bacterial pneumonia, it’s best not to push for an antibiotic. Overuse of antibiotics can have a number of ill effects, including putting you at risk for C. diff, a dangerous infection that can set in when your gut microbiome is compromised—a potential pitfall of antibiotics, especially for older adults.

Bottom line: A seemingly simple infection can take a turn for the worse quickly. Don’t be shy about seeking medical attention.