People of any age can get pneumonia, but it is more dangerous for young children, older adults, and those with weak immune systems. It is a common and potentially serious lung infection. Here's what pneumonia is, what causes it, how to recognize its symptoms, how to diagnose it, how to treat it, and how to prevent it.
A person with pneumonia suffers from inflammation of the air sacs (alveoli) of one or both lungs, where oxygen and carbon dioxide are exchanged. Symptoms such as cough, fever, chills, shortness of breath, and chest pain can occur when the lungs are inflamed. They can be filled with fluid or pus, making it more difficult for them to function.
Pneumonia can be caused by different types of germs, such as bacteria, viruses, fungi, or protozoa. Depending on the cause, pneumonia can be classified into different types:
The most common type of pneumonia is community-acquired pneumonia (CAP). It is caused by germs present in the environment, such as those from other people or animals. Streptococcus pneumoniae, Mycoplasma pneumoniae, Haemophilus influenzae, Chlamydia pneumoniae, Legionella pneumophila, and influenza virus are some of the common causes of CAP.
A hospital-acquired pneumonia (HAP) is pneumonia that occurs during or after a stay in a hospital or healthcare facility. Acinetobacter baumannii, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Pseudomonas aeruginosa are among the most common germs that cause it.
Those who have been on mechanical ventilation (breathing machines) for more than 48 hours can develop ventilator-associated pneumonia (VAP). As air is delivered to the lungs, it is caused by bacteria, including Escherichia coli, Enterobacter spp., and Serratia marcescens, that grow in the tubes and equipment.
Aspiration pneumonia occurs when you inhale food, liquids, vomit, or saliva into your lungs. It can cause chemical irritation and a bacterial infection of the lung tissue. It is more common in people with difficulty swallowing, such as those with stroke, dementia, or neurological disorders.
Pneumocystis jirovecii, Coccidioides, Histoplasma, and Aspergillus are some of the fungi that can cause fungal pneumonia. It is rare in healthy people, but it can affect those with a weakened immune system, such as HIV/AIDS, cancer, or organ transplants.
People who have weakened immune systems or travel to areas where these parasites are endemic or who live in parasite-infected areas may suffer from parasitic pneumonia.
The symptoms of pneumonia can vary depending on the type, cause, and severity of the infection. Some common symptoms are:
Cough, which may produce mucus or pus
Fever, which may be high or low
Chills and sweating
Shortness of breath or difficulty breathing
Chest pain, which may worsen when you cough or breathe deeply
Fatigue and weakness
Loss of appetite and weight loss
Nausea, vomiting, or diarrhea
Some people may also have confusion, headache, joint pain, or skin rash. In some cases, pneumonia can cause complications, such as:
Bacteremia, which is a spread of the infection to the bloodstream
Lung abscess, which is a collection of pus in the lung
Pleural effusion, which is a buildup of fluid in the space between the lung and the chest wall
Empyema, which is a collection of pus in the pleural space
Acute respiratory distress syndrome (ARDS), which is a severe form of lung injury that can lead to respiratory failure
Sepsis, which is a life-threatening response of the body to infection that can cause organ damage and shock
To diagnose pneumonia, your doctor will ask you about your symptoms, medical history, and possible exposure to germs. Your doctor will also examine you and listen to your lungs with a stethoscope. You may also need some tests, such as:
Chest X-ray, which can show the presence and extent of the infection in your lungs
Blood tests, which can check your white blood cell count, blood cultures, and inflammatory markers
Sputum tests, which can analyze the mucus or pus that you cough up to identify the cause of the infection
Urine tests, which can detect some bacteria that cause pneumonia, such as Streptococcus pneumoniae and Legionella pneumophila
Pulse oximetry, which can measure the oxygen level in your blood
CT scan, which can provide a more detailed image of your lungs and chest
Bronchoscopy, which can allow your doctor to look inside your airways and take samples of lung tissue or fluid
The treatment of pneumonia depends on the type, cause, and severity of the infection. Some general principles are:
Depending on the type of bacteria you have and how well you respond to treatment, antibiotics may be needed to treat bacterial pneumonia for 5 to 14 days. Even if you feel better, it is important to finish the antibiotics prescribed by your doctor to prevent the infection from returning or becoming resistant.
Antivirals are used to treat viral pneumonia, such as influenza or COVID-19. Treatment usually lasts for 5 to 10 days. They are most effective if started within 48 hours of signs of illness.
Fungal pneumonia is treated with antifungals, which are often taken for several weeks or months, depending on the type of fungus and your response to treatment. Antifungals can have serious side effects, so you must be monitored closely by your physician.
You can take either over-the-counter drugs, such as acetaminophen or ibuprofen, or prescription drugs, such as codeine or morphine, depending on the severity of your symptoms.
Cough suppressants, which reduce coughing and make you more comfortable. Depending on how severe your symptoms are and your doctor's advice, you may need to take over-the-counter drugs like dextromethorphan or guaifenesin or a prescription drug like benzonatate or hydrocodone. If you have a productive cough, however, you should not take cough suppressants because they can interfere with the clearance of mucus.
If you have low oxygen levels in your blood, you may need to use a nasal cannula, a face mask, or a ventilator depending on the severity of your condition.
During nausea, vomiting, or diarrhea, fluids and nutrition are used to keep you hydrated and nourished. Depending on your condition and your doctor's advice, you may need to drink oral rehydration solutions, such as Pedialyte or Gatorade, or receive intravenous fluids. To help your body fight the infection and recover from it, you may also need to eat a balanced diet containing protein, vitamins, and minerals.
Some people may need to be hospitalized for pneumonia, especially if they have severe symptoms, complications, or risk factors, such as:
Age over 65 or under 2 years
Chronic lung diseases, such as asthma or COPD
Heart diseases, such as heart failure or coronary artery disease
Diabetes or kidney diseases
Liver diseases or alcoholism
Cancer or immunosuppression
Neurological disorders or difficulty swallowing
Pregnancy or recent childbirth
Smoking or drug abuse
Malnutrition or dehydration
The best way to prevent pneumonia is to avoid getting infected by germs that cause it. Some preventive measures are:
Some of the most common causes of pneumonia, including Streptococcus pneumoniae, Haemophilus influenzae, influenza virus, and COVID-19, can be prevented by vaccination. In light of your age, health status, and exposure risk, you should discuss which vaccinations you need and when you should get them with your doctor.
The prevention of pneumonia can be achieved by maintaining good hygiene. Before and after touching your face, nose, mouth, or eyes, or coughing or sneezing, you should wash your hands frequently with soap and water or use alcohol-based hand sanitizer. When coughing or sneezing, cover your mouth and nose with a tissue or elbow, and dispose of the tissue properly. It is also advisable not to share personal items, such as cups, utensils, or toothbrushes.
It is important to avoid close contact with people who are ill, especially those who have fevers, coughs, or shortness of breath, which can reduce your exposure to the germs that cause pneumonia.
