Chronic Respiratory Disease

Chronic Respiratory Disease

When you can’t breathe, nothing else matters®.

Lung cancer is the #1 cancer killer of both women and men in the United States.

The 8 Most Common Types of Respiratory Disease

• Asthma.
• COPD.
• Cystic Fibrosis.
• Lung Cancer.
• Tuberculosis.
• Bronchitis.
• Pneumonia.
• Emphysema.

Lung diseases are some of the most common medical conditions in the world. Tens of millions of people have lung disease in the U.S. alone. Smoking, infections, and genes cause most lung diseases. 
Your lungs are part of a complex system, expanding and relaxing thousands of times each day to bring in oxygen and send out carbon dioxide. Lung disease can happen when there are problems in any part of this system.

Lung Diseases Affecting the Airways

Your windpipe (trachea) branches into tubes called bronchi, which in turn become smaller tubes throughout your lungs. Diseases that can affect these airways include:

• Asthma. Your airways are constantly inflamed and may spasm, causing wheezing and shortness of breath. Allergies, infections, or pollution can trigger asthma symptoms.
• Chronic obstructive pulmonary disease(COPD). With this lung condition, you can’t exhale the way you usually would, which causes trouble breathing.
• Chronic bronchitis. This form of COPD brings a long-term wet cough.
• Emphysema. Lung damage allows air to be trapped in your lungs in this form of COPD. Trouble blowing air out is its hallmark.
• Acute bronchitis.This sudden infection of your airways is usually caused by a virus.
• Cystic fibrosis. With this condition, you have trouble clearing mucus out of your bronchi. This leads to repeated lung infections.

Lung Diseases Affecting the Air Sacs (Alveoli)

Your airways branch into tiny tubes (bronchioles) that end in clusters of air sacs called alveoli. These air sacs make up most of your lung tissue. Lung diseases affecting your alveoli include:

• Pneumonia. An infection of your alveoli, usually by bacteria or viruses, including the coronavirus that causes COVID-19.
• Tuberculosis Pneumonia that slowly gets worse, caused by the bacteria Mycobacterium tuberculosis.
• Emphysema. This happens when the fragile links between alveoli are damaged. Smoking is the usual cause. (Emphysema also limits airflow, affecting your airways.)
• Pulmonary edema. Fluid leaks out of the small blood vessels of your lung into the air sacs and the area around them. One form is caused by heart failure and back pressure in your lungs' blood vessels. In another form, injury to your lung causes the leak of fluid.
• Lung cancer. It has many forms and may start in any part of your lungs. It most often happens in the main part of your lung, in or near the air sacs.
• Acute respiratory distress syndrome (ARDS). This is a severe, sudden injury to the lungs from a serious illness. COVID-19 is one example. Many people who have ARDS need help breathing from a machine called a ventilator until their lungs recover.
• Pneumoconiosis. This is a category of conditions caused by inhaling something that injures your lungs. Examples include black lung disease from coal dust and asbestosis from asbestos dust.

Lung Diseases Affecting the Interstitium

The interstitium is the thin, delicate lining between your alveoli. Tiny blood vessels run through the interstitium and let gas transfer between the alveoli and your blood. Various lung diseases affect the interstitium:

• Interstitial lung disease (ILD). This is a group of lung conditions that includes sarcoidosis, idiopathic pulmonary fibrosis, and autoimmune disease.
• Pneumonia and pulmonary edema can also affect your interstitium.

Lung Diseases Affecting Blood Vessels

The right side of your heart gets low-oxygen blood from your veins. It pumps blood into your lungs through the pulmonary arteries. These blood vessels can have diseases, as well.

• Pulmonary embolism(PE). A blood clot (usually in a deep leg vein, called deep vein thrombosis) breaks off, travels to your heart, and gets pumped into your lungs. The clot sticks in a pulmonary artery, often causing shortness of breath and low blood oxygen levels.
• Pulmonary hypertension. Many conditions can cause high blood pressure in your pulmonary arteries. This can lead to shortness of breath and chest pain. If your doctor can’t find a cause, they’ll call it idiopathic pulmonary arterial hypertension.

Lung Diseases Affecting the Pleura

The pleura is the thin lining that surrounds your lung and lines the inside of your chest wall. A tiny layer of fluid lets the pleura on your lung's surface slide along the chest wall with each breath. Lung diseases of the pleura include:

• Pleural effusion. Fluid collects in the space between your lung and the chest wall. Pneumonia or heart failure usually causes this. Large pleural effusions can make it hard to breathe and may need to be drained.
• Pneumothorax. Air may get into the space between your chest wall and the lung, collapsing the lung.
• Mesothelioma. This is a rare form of cancer that forms on the pleura. Mesothelioma tends to happen several decades after you come into contact with asbestos.

Lung Diseases Affecting the Chest Wall

Your chest wall also plays an important role in breathing. Muscles connect your ribs to each other, helping your chest expand. Your diaphragm descends with each breath, also causing chest expansion. Diseases that affect your chest wall include:

• Obesity hypoventilation syndrome. Extra weight on your chest and belly can make it hard for your chest to expand. This may cause serious breathing problems.
• Neuromuscular disorders. You might have trouble breathing when the nerves that control your respiratory muscles don’t work the way they should. Amyotrophic lateral sclerosis and myasthenia gravis are examples of neuromuscular lung disease.

Common Lung Diagnostic Tests

If you have trouble breathing, your doctor may recommend a few tests to figure out what’s causing it.
Some measure how much air you breathe in or out or how much oxygen is going from your lungs to the rest of your body, while others can show if you have an infection or another problem that’s keeping you from breathing well.

Simple Tests

Spirometry. This is the simplest and most common lung test. You breathe in and out as hard as you can through a tube, and your doctor measures the volume of air exhaled at specific time points during a forceful and complete exhalation after a maximal inhalation. It can help diagnose conditions that affect how much air your lungs can hold, like chronic obstructive pulmonary disease (COPD). Doctors will test spirometry before and after albuterol, bronchodilator and see if there is an improvement with the medications which is seen in asthma, but not in COPD.
Challenge test. Your doctor will do spirometry first, then ask you to breathe in a spray of a drug called methacholine, which can irritate your airways and make them narrow. Your doctor will do another spirometry to see how the spray affects your breathing. They’ll repeat this with small doses until you start to wheeze or feel short of breath. Your doctor may give you medicine to open your airways again. This test is not routinely done to diagnose asthma.
If your doctor thinks you have a condition called exercise-induced asthma, they may do a similar version of this test called an exercise challenge. Instead of methacholine, your doctor will ask you to use a treadmill or stationary bike and see how that physical activity affects your breathing.
FeNO test. With this, you blow slowly and steadily into a device, and it measures how much nitric oxide is in the air you breathe out. It’s used with people who have certain types of asthma to see if there’s any inflammation in their lungs and how well steroids are working to control inflammation. It is safe, noninvasive, can be done over and over and is used in kids when spirometry is difficult to perform. 
Peak flow measurement. This uses a small plastic device to see how much air you can blow out of your lungs. You take a deep breath and then breathe out as fast and hard as you can. It’s most often used in people with asthma, a condition that narrows the air passages that lead to your lungs. The test compares each result with your best reading. A number above 80% of your best result is good; a number below 50% means you should get help right away. This test can give you advance warning of an asthma attack.
Pulse oximetry, or “pulse ox.” This test uses a device that measures how much oxygen your red blood cells are carrying. The device is usually clipped onto your fingertip, but it can be attached to your nose, foot, ears, or toes. The results are shown as a percentage, with a good result being over 90%. If your numbers are below 90%, your doctor may give you oxygen to help you breathe.

Advanced Tests

Plethysmography. This gives your doctor a more exact measurement of how much air your lungs can hold. You’ll sit in a booth with a clip holding your nose shut while you breathe through a mouthpiece. This can tell your doctor if your airways have narrowed or how much an ongoing problem like asthma or COPD has hurt your breathing. It can also help your doctor decide what medicines you need or if you might need surgery.
Diffusion capacity test. This measures how well your lungs pass oxygen to your blood. You’ll breathe in and out through a tube for several minutes, and your doctor may take a sample of your blood to help calculate the results. This test can show if your lungs have been damaged or if you have problems with blood flow.

Imaging Tests

Chest X-ray. This can be used to look for problems like pneumonia, an infection that makes fluid build up in your lungs. It also can help diagnose cancer or a buildup of scar tissue in your lungs known as pulmonary fibrosis.
Computerized tomography (CT) or positron emission tomography (PET) scans. These are more advanced imaging tests that can be used to find problems that an X-ray might not until they’re further along, like cancer. A CT scan is a series of X-rays taken from different angles that are put together to make a more complete picture. A PET scan uses a special dye that lets your doctor see parts of your body more clearly.
Chest ultrasound. This uses high-frequency sound waves to make an image of your lungs. It can help your doctor see if there’s any fluid buildup in or around your lungs.
Pulmonary angiogram. This is a type of CT scan that focuses on the pulmonary arteries -- the blood vessels that connect your heart and lungs. It’s used to spot a potentially life-threatening blood clot in your lungs known as a pulmonary embolism.

Invasive Tests

Bronchoscopy. Your doctor will slide a small tube with a camera on the end into your airways. The camera lets them look inside those passages for things like mucus, blood, or tumors. You’ll be given medicine to make you sleepy or to numb your air passages before the test, and you may get oxygen during the test. You may have a sore throat afterward. A bronchoscope can also collect small samples of tissue for testing. This is known as a biopsy, and it’s commonly used to look for diseases like cancer.
Mediastinoscopy. This uses a similar tool to look at the space between your right and left lung lobes behind your breastbone. But doctors have to cut a small hole into your chest to put the device in. Because of that, you’ll be given medicine to make you sleep during the procedure. It’s usually done to take out lymph nodes and look for signs of cancer that has spread from your lungs. This can help doctors figure out the best way to treat the disease.
Pleural biopsy: Your lungs are surrounded by a layer of tissue called the pleura, and some health problems can make fluid build up in the space between the pleura and your lungs. If that’s the case, this test might help your doctor figure out what’s causing it. A pleural biopsy usually uses a needle to get a sample of the tissue. The needle goes into your chest between the ribs on your back. Your doctor will give you medicine to numb the skin around that spot before the test.
Source: https://www.webmd.com/lung/breathing-diagnostic-tests

American Lung Association

See: https://www.lung.org/lung-health-diseases
Source: https://www.lung.org/