When it first comes on, pneumonia symptoms often feel like the garden-variety  flu — coughing, fever, and shortness of breath. But if several days of home remedies don’t help you feel better or you get worse, you might have pneumonia.

Pneumonia, which can be caused by bacteria, viruses, or fungi, is not something to be taken lightly — more than 30,000 people die every year from this serious lung infection. And it’s especially worrisome if you’re elderly, your immune system isn’t in tiptop shape, or you suffer from a chronic illness, such as congestive heart failure, diabetes, liver disease, or COPD (chronic obstructive pulmonary disease).

“People with these conditions are more likely to be infected with a broader range of  organisms than patients who are healthy,” says Fredrick M. Abrahamian, DO, FACEP,  director of education in the Department of Emergency Medicine, Olive View-UCLA  Medical Center in Sylmar, Calif.

Circumstances that can affect the immune system include HIV infection, sickle cell disease, removal of the spleen, chemotherapy treatments, or steroid medications taken for a long time. Smoking and alcohol abuse can also make you more vulnerable because they interfere with your body’s ability to fight off  opportunistic invaders.

“Patients should give their doctor a detailed medical history so he or she can make accurate therapeutic decisions,” says Dr. Abrahamian. “It is also extremely important to tell your doctor if you were recently hospitalized or treated with an antibiotic for any type of infection.”

Signs of pneumonia include fever, cough, chest pains that make breathing difficult, and chills that make your body quiver. “Typically, you’ll have lower respiratory symptoms — chest pains, a hard time breathing, and even upper back pain, rather than the sinus congestion, runny nose, and stuffy head of a cold,”  Dr. Abrahamian explains. Because pneumonia can potentially escalate into a  life-threatening illness, see your doctor as soon as possible if you have any of these symptoms, especially if you fall into any of the high-risk categories that weaken your immune system.

If your doctor suspects you have pneumonia, you may undergo a chest  X-ray to confirm the diagnosis. Bacterial pneumonia is normally treated with antibiotics, although you should tell your doctor if you’ve taken antibiotics in the past three months, because you may be infected with drug-resistant germs that are harder to get rid of. Similarly, fungal lung infections can be treated with  antifungal medications. Unfortunately, antibiotics don’t work against viral pneumonia, which is normally treated with rest and drinking plenty of fluids. Liquids ward off dehydration and can help loosen mucus in your lungs.

But the best “remedy” is to prevent getting pneumonia in the first place.  Here are some prevention tips:

• Get vaccinated. Pneumonia vaccines are recommended for people older than age 50, for those at high risk, and for children 2 years of age or younger. Vaccinations can help protect you from getting very sick and allow your body  to build immunity against infections.  Try to avoid close contact with people who are sick, especially if your immune system is weak because of illness such as diabetes or emphysema.
• Wash your hands. Because your hands are in almost constant contact with germs that can cause infections, washing your hands often and thoroughly can reduce risks. 
• Don’t smoke. Smoking destroys your lungs’ natural defenses against respiratory infections.
• Take care of yourself. Proper rest, eating a diet rich in fruits and vegetables, and getting a moderate amount of exercise every day can bolster your immune system.