- What is Emphysema?
- Causes of Emphysema
- Emphysema Symptoms
- Shortness of breath
- Barrel-shaped chest
- Chest pain
- Emphysema Diagnosis
- Physical exam
- Pulmonary function tests (PFTs)
- Complete blood count
- Chest x-ray
- CT scan of the chest
- Emphysema Stages
- GOLD Staging System
- BODE Index
- Emphysema Life Expectancy
- Emphysema Treatment
What is Emphysema?
Emphysema is a chronic disorder caused by the gradual destruction of the alveoli, or the air sacs in the lungs, causing breathing difficulty and shortness of breath. It is referred to as Chronic Obstructive Pulmonary Disease (COPD), along with chronic bronchitis .
Statistics say that more than 10 million people have emphysema. In addition, emphysema and chronic bronchitis are ranked fourth in the leading causes of mortality in the USA .
What usually happens in emphysema is that the linings of the alveoli become thinner over time. Air holes are formed, where the air inhaled becomes trapped, making it difficult to breathe it out. The lungs become enlarged over time, making it more difficult to breathe . Elastic fibers that aid in opening the air sacs during breathing are also destroyed, thus the lungs collapse, trapping the air during exhalation .
Picture 1: Normal alveoli vs damaged alveoli during emphysema
Image source: drugs.com
Causes of Emphysema
There are several causes of emphysema, but the primary cause of emphysema is smoking . The smoke from cigarettes can be inhaled deep into the alveoli, causing damage to these air sacs . It is reported that the toxins in cigarettes cause the destruction of the alveoli.
However, not all smokers develop the disease. In fact, most heavy smokers do not get affected by the disease. Whoever is at more risk to develop the disease is still unknown .
Other sources of smoke can cause damage to the alveoli as well, leading to emphysema. In fact, research has proved that people who are exposed to secondhand smoke are at higher risk of having emphysema than the smokers themselves .
Alpha-1 antitrypsin deficiency
Compared to smoking, this is a relatively less important cause of emphysema.Alpha-1 antitrypsin is a protein naturally found in the body, and it acts by preventing white blood cells from attacking and destroying normal cells and tissues. Genetic problems cause this protein to become deficient, causing white blood cells to attack normal lung tissue. 
It is not known how many people develop emphysema because of this condition, but people who suffer from alpha-1 antitrypsin deficiency often develop emphysema at a younger age.
Emphysema is also linked with air pollution, but emphysema caused by air pollution may take years to develop. 
Shortness of breath
The main symptom of emphysema is shortness of breath, which worsens as the disease becomes severe . At first, the patient becomes breathless after doing an activity, but in advanced stages, breathlessness is experienced even when the patient is at rest .
This is a characteristic of COPD patients. The chest area becomes literally barrel-shaped because the ribs expand due to over-inflation of the lungs. This develops during the latter stages of the disease. 
Picture 2: Barrel-shaped chest
Image source: img.tfd.com
Wheezing is the sound produced during breathing, which is similar in asthma patients . It may be heard during inhaling, exhaling or both, but most commonly, it is heard during the early part of exhaling .
Emphysema patients also suffer from persistent cough, which may be productive (with sputum) or non-productive (without sputum) .
This is experienced due to difficulty in breathing and tightness caused by the overinflated lungs.  Other less common symptoms experienced by emphysema patients include:
- Loss of appetite
- Decreased sexual function
- Improper sleep
This is important in moderate to severe cases of emphysema because the physical symptoms are more evident. Barrel-shaped chest, cyanosis or blue lips, and malnutrition can be seen through direct observation. Using a stethoscope, decreased breathing sounds can also be observed. 
Pulmonary function tests (PFTs)
PFTs are done by letting the patient breath in a tube while staying in a closed booth. It measures the following:
- Capacity of lungs to hold air
- Speed of exhaling air from the lungs
- Amount of air trapped in the lungs after exhaling
- Any improvement in breathing when bronchodilators are administered
Complete blood count
In advanced emphysema, red blood cell count may increase. Elevated amounts of white blood cells may also indicate an infection.
Enlarged lungs are visible through chest x-rays. However, in milder stages, the lungs appear to be normal.
CT scan of the chest
Computed tomography, or CT scan, can show air holes in the alveoli, which is the main cause for the difficulty in breathing.
There are two ways to classify the stages of emphysema- the GOLD staging system and the BODE index .
GOLD Staging System
This staging system is created by the Global Initiative for Chronic Obstructive Lung Disease, and is the most commonly used staging system for emphysema. It is based on the amount of air forcefully exhaled by a person within one second, known as the forced expiratory volume (FEV1).The following are the stages based on the GOLD system:
- Stage 1 (Mild): FEV1 ≥ 80%
- Stage 2 (Moderate): FEV1 ≥ 50%, <80%
- Stage 3 (Severe): FEV1 ≥ 30%, <50%
- Stage 4 (Very severe): FEV1 < 30%, or <50% accompanied by low oxygen levels
The BODE index assesses the effect of emphysema in multiple aspects of the patient’s life which affect the life expectancy of each patient. The severity of emphysema is evaluated according to:
- Body mass index (B), measured in terms of the patient’s weight versus height (kg/m2)
- Airflow limitation or obstruction (O), measured using FEV1
- Breathlessness or dyspnea (D), evaluated using a questionnaire
- Exercise capacity (E), measured by the distance the patient can walk within 6 minutes
Picture 3: BODE index scoring
Image source: livedoor.blogimg.jp
The higher the BODE index score, the lower the chance of being cured from the disease is lower.
Emphysema Life Expectancy
The prognosis of emphysema may be different from patient to patient, but the staging system, especially the BODE index, can generalize how well a patient can improve from the disease. The following information on life expectancy is generalized from both the GOLD and BODE systems:
- Mild emphysema- 80% of patients are alive after 4 years
- Moderate emphysema- 60-70% are alive after 4 years
- Severe emphysema- 50% are alive after 4 years
- Very severe emphysema- short life expectancy
While emphysema cannot be cured, there are still ways of improving the symptoms experienced during emphysema. This helps reduce the frequency of hospitalizations, as well as preserve lung function despite the damage.  The most important treatment is quitting smoking. The patient must also avoid being exposed to smoky places . Drugs can be given to help in smoking cessation, such as bupoprion hydrochloride and varenicline .
To relieve cough and shortness of breath, bronchodilators are usually prescribed. Bronchodilators act by relaxing the obstructed airways, making it easier to breathe . Examples include albuterol and ipratropium, which are short-acting, and salmeterol, formoterol and titropium, which are long-acting. These can be administered as a solution, or by using puffers and nebulizers .
Inhaled corticosteroids can also be given to reduce the inflammation in the airways. Examples include fluticasone and beclomethasone . However, prolonged use of corticosteroids leads to increased blood pressure and weak bones, as well as diabetes and cataracts .
Aside from medications, the patient can also undergo pulmonary rehabilitation, which includes breathing techniques and exercises. Oxygen supplementation is also done in cases of low oxygen levels. 
For very severe cases, a surgery is sometimes necessary. Lung volume reduction or lung transplant can be performed. In lung volume reduction, damaged parts of the lung are sliced off, allowing the remaining functional parts to work more efficiently. Lung transplant, on the other hand, is done when other options have already failed.