Pneumonia is an infection that inflames the air sacs in one or both lungs. The air sacs may fill with fluid or pus, causing cough with phlegm or pus, fever, chills and difficulty breathing.
A variety of organisms, including bacteria, viruses and fungi, can cause pneumonia.
Pneumonia can range in seriousness from mild to life-threatening. It is most serious for infants and young children, people older than age 65, and people with underlying health problems or weakened immune systems.
Antibiotics and antiviral medications can treat many common forms of pneumonia.
The signs and symptoms of pneumonia vary from mild to severe, depending upon factors such as the type of germ causing the infection and your age and overall health. Mild signs and symptoms often are similar to those of a cold or flu, but they last longer.
Newborns and infants may not show any sign of the infection. Or they may vomit, have a fever and cough, appear restless or tired and without energy, or have difficulty breathing and eating.
Older people who have pneumonia sometimes have sudden changes in mental awareness.
WHEN TO SEE A DOCTOR See your doctor if you have difficulty breathing, chest pain, persistent fever of 39 C or higher or persistent cough, especially if you are coughing up pus.
It's especially important to see a doctor if:
A child with signs and symptoms is younger than age 2
You are older than age 65
You have an underlying health condition or weakened immune system
You're having chemotherapy or taking medication that suppresses your immune system
For some older adults and people with heart failure or lung ailments, pneumonia can quickly become a life-threatening condition.
Pneumonia has many possible causes. The most common are bacteria and viruses in the air we breathe. Your body usually prevents these germs from infecting your lungs. But sometimes these germs can overpower your immune system, even if your health is generally good.
Pneumonia is classified according to the types of germs that cause it, and where you acquired the infection.
Community-acquired pneumonia Community-acquired pneumonia is the most common type of pneumonia. It occurs outside of hospitals and other health care facilities, and may be caused by:
Bacteria, such as Streptococcus pneumoniae. Bacterial community-acquired pneumonia can occur on its own or after you have a cold or respiratory flu. This type of pneumonia often affects one area (lobe) of the lung, a condition called lobar pneumonia.
Bacteria-like organisms, such as Mycoplasma pneumoniae, which typically produce milder signs and symptoms than do other types of pneumonia. "Walking pneumonia," a term used to describe pneumonia that isn't severe enough to require bed rest, may result from Mycoplasma pneumoniae.
Viruses, including some that are the same type of viruses that cause colds and flu. Viruses are the most common cause of pneumonia in children younger than 2 years. Viral pneumonia is usually mild. But viral pneumonia caused by certain influenza viruses, such as sudden acute respiratory syndrome (SARS), can become very serious.
Fungi, which can be found in soil and in bird droppings. This type of pneumonia is most common in people with an underlying health problem or weakened immune system and in people who have inhaled a large dose of the organisms.
Hospital-acquired pneumonia is a bacterial infection that occurs in people 48 hours or more after being hospitalized for another condition. Hospital-acquired pneumonia can be serious because the bacteria causing it may be more resistant to antibiotics.
People who are on a breathing machine (ventilator), often used in intensive care units, are at higher risk of this type of pneumonia.
Health care-acquired pneumonia Health care-acquired pneumonia is a bacterial infection that occurs in people who are living in long-term care facilities or have been treated in outpatient clinics, including kidney dialysis centers. Like hospital-acquired pneumonia, health care-acquired pneumonia can be caused by bacteria more resistant to antibiotics.
Aspiration pneumonia Aspiration pneumonia occurs when you inhale food, drink, vomit or saliva into your lungs. This aspiration may happen if something disturbs your normal gag reflex, such as a brain injury, swallowing problem, or excessive use of alcohol or drugs.
Pneumonia can affect anyone. But the two age groups at highest risk are:
Infants and children younger than age 2 years, because their immune systems are still developing
People older than age 65
Other risk factors include:
Certain chronic diseases, such as asthma, chronic obstructive pulmonary disease and heart disease
Weakened or suppressed immune system, due to factors such as HIV/AIDS, organ transplant, chemotherapy for cancer or long-term steroid use
Smoking, which damages your body's natural defenses against the bacteria and viruses that cause pneumonia
Being placed on a ventilator while hospitalized
Often, people who have pneumonia can be treated successfully with medication. But some people, especially those in high-risk groups, may experience complications, including:
Bacteria in the bloodstream (bacteremia). Bacteria that enter the bloodstream from your lungs can spread the infection to other organs, potentially causing organ failure.
Lung abscess. An abscess occurs if pus forms in a cavity in the lung. An abscess is usually treated with antibiotics. Sometimes, surgery or drainage with a long needle or tube placed into the abscess is needed to remove the pus.
Fluid accumulation around your lungs (pleural effusion). Pneumonia may cause fluid to build up in the thin space between layers of tissue that line the lungs and chest cavity (pleura). If the fluid becomes infected, you may need to have it drained through a chest tube or removed with surgery.
Difficulty breathing. If your pneumonia is severe or you have chronic underlying lung diseases, you may have trouble breathing in enough oxygen. You may need to be hospitalized and use a mechanical ventilator while your lung heals.
Tests and diagnosis
Your doctor will start by asking about your medical history and doing a physical exam, including listening to your lungs with a stethoscope to check for abnormal bubbling or crackling sounds that indicate the presence of thick liquid.
If pneumonia is suspected, your doctor may recommend:
Chest X-rays, to confirm the presence of pneumonia and determine the extent and location of the infection.
Blood tests, to confirm the presence of infection and to try to identify the type of organism causing the infection. Precise identification occurs in only about half of people with pneumonia.
Pulse oximetry, to measure the oxygen level in your blood. Pneumonia can prevent your lungs from moving enough oxygen into your bloodstream.
Sputum test. A sample of fluid from yours lungs (sputum) is taken after a deep cough, and analyzed to pinpoint the type of infection.
If you are older than age 65, are in the hospital or have serious symptoms or an underlying health condition, your doctor may recommend:
Pleural fluid culture. A fluid sample is taken from the pleural area and analyzed to help determine the type of infection.
Bronchoscopy. A thin, flexible tube with a camera is inserted down your throat and through your airways to check whether something is blocking the airways or whether something else is contributing to your pneumonia.
If your pneumonia isn't clearing as quickly as expected, your doctor may recommend a chest CT scan to obtain a more detailed image of your lungs.
Treatments and drugs
Treatment for pneumonia involves curing the infection and preventing any complications.
People who have community-acquired pneumonia usually can be treated at home with medication. Although your symptoms may ease in a few days or weeks, tiredness can persist for a month or more.
Your doctor will likely recommend a follow-up chest X-ray to check that the infection is clearing. It may be safe to stop treatment even if your X-ray isn't completely normal. Only about half of chest X-rays in people with community-acquired pneumonia are normal after 28 days of treatment.
Specific treatments depend on the type and severity of your pneumonia, and your age and overall health. The options include:
Antibiotics, to treat bacterial pneumonia. It may take time to identify the type of bacteria causing your pneumonia and to choose the best antibiotic to treat it. Symptoms often improve within three days, although improvement usually takes twice as long in smokers. If your symptoms don't improve, your doctor may recommend a different antibiotic.
Antiviral medications, to treat viral pneumonia. Symptoms generally improve in one to three weeks.
Fever reducers, such as aspirin or ibuprofen.
Cough medicine, to calm your cough so you can rest. Because coughing helps loosen and move fluid from your lungs, it's a good idea not to eliminate your cough completely.
If you need to be placed on a ventilator or your symptoms are severe, you may need to be admitted to an intensive care unit.
Children may be hospitalized if they:
Are younger than age 3 months
Are excessively sleepy
Have trouble breathing
Have low blood oxygen levels
Have a lower than normal temperature
Lifestyle and home remedies
To help you recover more quickly and decrease your risk of complications:
Get plenty of rest. Even when you start to feel better, be careful not to overdo it.
Stay home from school or work until after your temperature returns to normal and you stop coughing up mucus. Because pneumonia can recur, it's better not to return to a full workload until you're sure you're well. Ask your doctor if you're not sure.
Drink plenty of fluids, especially water, to help loosen mucus in your lungs.
Take the entire course of any prescribed medications. If you stop medication too soon, your lungs may continue to harbor bacteria that can multiply and cause your pneumonia to recur.
To help prevent pneumonia:
Get a seasonal flu shot. The influenza virus can be a direct cause of viral pneumonia. Bacterial pneumonia is also a common complication of the flu. A yearly flu shot provides significant protection.
Link to the Vaccination
Get a pneumonia vaccination. Doctors recommend a one-time vaccine against Streptococcus pneumoniae bacteria (pneumococcus) for everyone older than age 65, as well as for people of any age residing in nursing homes and long-term care facilities, and for smokers. The vaccine is especially recommended for anyone at high risk of pneumococcal pneumonia. Some doctors recommend a booster shot five years after the first dose.
Have your child vaccinated. Doctors recommend a different pneumonia vaccine for all children younger than age 2 and for children ages 2 to 5 years who are at particular risk of pneumococcal disease. Children who attend a group day care center should also get the vaccine. Doctors also recommend seasonal flu shots for children older than six months.
Practice good hygiene. To protect yourself against ordinary respiratory infections that sometimes lead to pneumonia, wash your hands regularly or use an alcohol-based hand sanitizer.
Don't smoke. Smoking damages your lungs' natural defenses against respiratory infections.
Stay rested and fit. Proper rest, a healthy diet and moderate exercise can help keep your immune system strong.
Set an example. Stay home when you're sick. When you're in public and have a cold, catch your coughs and sneezes in the inner crook of your elbow.
Chronic obstructive pulmonary disease (COPD) is one of the most common lung diseases. It makes it difficult to breathe. There are two main forms of COPD:
Chronic bronchitis, which involves a long-term cough with mucus
Emphysema, which involves destruction of the lungs over time
Most people with COPD have a combination of both conditions.
Smoking is the leading cause of COPD. The more a person smokes, the more likely that person will develop COPD. However, some people smoke for years and never get COPD.
In rare cases, nonsmokers who lack a protein called alpha-1 antitrypsin can develop emphysema.
Other risk factors for COPD are:
Exposure to certain gases or fumes in the workplace
Exposure to heavy amounts of secondhand smoke and pollution
Frequent use of cooking fire without proper ventilation
Cough, with or without mucus
Many respiratory infections
Shortness of breath (dyspnea) that gets worse with mild activity
Trouble catching one's breath
Because the symptoms of COPD develop slowly, some people may not know that they are sick.
EXAMS AND TESTS
The best test for COPD is a lung function test called spirometry. This involves blowing out as hard as possible into a small machine that tests lung capacity. The results can be checked right away, and the test does not involve exercising, drawing blood, or exposure to radiation.
Using a stethoscope to listen to the lungs can also be helpful. However, sometimes the lungs sound normal even when COPD is present.
Pictures of the lungs (such as x-rays and CT scans) can be helpful, but sometimes look normal even when a person has COPD (especially chest x-ray).
Sometimes patients need to have a blood test (called arterial blood gas) to measure the amounts of oxygen and carbon dioxide in the blood.
There is no cure for COPD. However, there are many things you can do to relieve symptoms and keep the disease from getting worse.
Persons with COPD MUST stop smoking. This is the best way to slow down the lung damage.
Medications used to treat COPD include:
Inhalers (bronchodilators) to open the airways
Inhaled steroids to reduce lung inflammation
Anti-inflammatory medications are sometimes used
In severe cases or during flare-ups, you may need to receive:
Steroids by mouth or through a vein (intravenously)
Bronchodilators through a nebulizer
Assistance during breathing from a machine
Antibiotics are prescribed during symptom flare-ups, because infections can make COPD worse.
You may need oxygen therapy at home if you have a low level of oxygen in your blood.
Pulmonary rehabilitation does not cure the lung disease, but it can teach you to breathe in a different way so you can stay active. Exercise can help maintain muscle strength in the legs.
Walk to build up strength.
Ask the doctor how far to walk.
Slowly increase how far you walk.
Try not to talk when you walk if you get short of breath.
Use pursed lip breathing when breathing out (to empty your lungs before the next breath)
Things you can do to make it easier for yourself around the home include:
Avoiding very cold air
Making sure no one smokes in your home
Reducing air pollution by getting rid of fireplace smoke and other irritants
Eat a healthy diet with fish, poultry, or lean meat, as well as fruits and vegetables. If it is hard to keep your weight up, talk to a doctor or dietitian about eating foods with more calories.
COPD is a long-term (chronic) illness. The disease will get worse more quickly if you do not stop smoking.
Patients with severe COPD will be short of breath with most activities and will be admitted to the hospital more often.
Breathing is a complex process. If injury, disease, or other factors affect any part of the process, you may have trouble breathing.
For example, the fine hairs (cilia) that line your upper airways may not trap all of the germs you breathe in. These germs can cause an infection in your bronchial tubes (bronchitis) or deep in your lungs (pneumonia). These infections cause a buildup of mucus or fluid that narrows the airways and limits airflow in and out of your lungs.
If you have asthma, breathing in certain substances that you're sensitive to can trigger your airways to narrow. This makes it hard for air to flow in and out of your lungs.
Over a long period, breathing in cigarette smoke or air pollutants can damage the airways and air sacs. This can lead to a disease called COPD (chronic obstructive pulmonary disease). COPD prevents proper airflow in and out of your lungs and can hinder gas exchange in the air sacs.
An important step to breathing is the movement of your diaphragm and other muscles in your chest, neck, and abdomen. This movement lets you inhale and exhale. Nerves that run from your brain to these muscles control their movement. Damage to these nerves in your upper spinal cord can cause breathing to stop, unless a machine is used to help you breathe. (This machine is called a ventilatoror a respirator.)
A steady flow of blood in the small blood vessels that surround your air sacs is vital for gas exchange. Long periods of inactivity or surgery can cause a blood clot called a pulmonary embolism (PE) to block a lung artery. A PE can reduce or block the flow of blood in the small blood vessels and hinder gas exchange.