Pneumonia: Symptoms, Causes, Treatment & Prevention

Pneumonia is a lung infection that fills air sacs with fluid or pus. You can get it from bacteria, viruses, or fungi. Symptoms often include cough, fever, shortness of breath, chest pain when breathing, and fatigue. Older adults, infants, and people with chronic illness face higher risk. Knowing when to seek care and how to prevent it can keep small problems from becoming medical emergencies.

How do you know it's pneumonia and not a bad cold? Look for persistent fever above 38°C (100.4°F), cough that produces yellow or green phlegm, breathlessness, or rapid breathing. If you feel confused, very weak, or have blue lips or fingertips, get urgent care. A doctor will usually listen to your lungs, order a chest X-ray, and may check blood or sputum to find the cause.

Common causes and who’s at risk

Bacterial pneumonia—often from Streptococcus pneumoniae—is common and usually treated with antibiotics. Viral pneumonia can come from influenza or COVID-19 and may not respond to antibiotics. Fungal pneumonia is rarer and affects people with weakened immune systems. Smoking, recent flu, weak immunity, chronic lung disease, and age increase your chances of getting pneumonia.

Treatment basics and home care

Treatment depends on the cause. Bacterial cases need antibiotics; viral cases might need antiviral drugs or just supportive care. If you have trouble breathing, low oxygen, severe chest pain, or dehydration, hospitals can give oxygen, IV fluids, and stronger treatments. At home, rest, fluids, fever control (acetaminophen or ibuprofen), and breathing exercises help. Finish the full antibiotic course even if you feel better. Follow-up is important—do a follow-up chest X-ray if your doctor recommends it, especially for smokers and older adults.

Prevention is simple and effective. Get vaccinated: pneumococcal vaccines and annual flu shots cut your risk. Wash hands, avoid close contact with sick people, and quit smoking. For people with chronic illness, keep regular doctor visits and manage conditions like diabetes and COPD to lower risk. If you live with someone who has pneumonia, good ventilation and masks during illness help reduce spread.

When to call a doctor: if symptoms worsen after 48–72 hours of treatment, if you can't keep liquids down, or if you develop high fever, severe breathlessness, or mental changes. For infants and older adults, seek care faster—these groups can deteriorate quickly. Ask your provider about pulse oximetry at home if you have chronic lung disease; it helps monitor oxygen levels between visits.

Quick practical tips: keep a thermometer and fever medicine handy, humidify dry air to ease coughing, and use a soft cough suppressant only at night if cough prevents sleep—avoid suppressants if you have thick phlegm. Keep medical records of previous chest infections and vaccinations—it speeds diagnosis. If you take antibiotics, store them out of reach of children and never share prescriptions.

If you get pneumonia more than once, ask about immune testing or swallowing checks. After recovery, do gentle exercise, eat protein-rich food, and practice breathing exercises for better lung strength and stamina.