What is COPD and Its Physiology

What is COPD and Its Physiology

Chronic obstructive pulmonary disease is known as COPD. COPD is a lung condition brought on by breathing difficulties brought on by obstructions in the lungs' airways. Even though COPD is a progressive condition, early detection and therapy may halt its development. Chronic bronchitis or emphysema can make COPD worse; some individuals get both conditions, which can cause further breathing issues. Emphysema and chronic bronchitis are sometimes seen by doctors as being different forms of COPD. Long-term lung tissue damage alters the physical structure of the lungs and clogs the airways with thick mucus. This lung tissue injury reduces compliance (the capacity of the lung tissue to expand). Due to the lungs' reduced compliance or flexibility, oxygen cannot reach the lung's air gaps, where the exchange of oxygen and carbon dioxide takes place. All of this causes coughing to expel the thick mucus, which ultimately causes breathing difficulties.

What are the Symptoms?

The main sign of COPD is shortness of breath. It results from blocked or congested airways and damaged or destroyed alveoli, which are where oxygen is absorbed and carbon dioxide is exhaled, and it happens throughout daily activities. Wheezing, tightness in the chest, and a persistent cough are some additional signs of COPD. The affected person may be easily fatigued, susceptible to repeated colds and flu illnesses, and prone to excessive mucus or sputum production. COPD symptoms gradually get worse, and those who have advanced COPD symptoms may:

  • Be obese from lack of exercise
  • Have muscle loss and declining endurance
  • Have morning headaches
  • Have a bluish or greyish color underneath the fingernails due to decreased oxygen levels in the blood
  • Conversely, some patients with COPD and emphysema may lose weight

Causes of COPD

A major factor in the development of COPD is smoking and exposure to secondhand smoke. Smoking is a factor in 85% to 90% of all COPD fatalities. The remaining causes are connected to environmental irritants (pollution), and a very small number are genetic diseases that are passed down through families (for example, people with Alpha-1 antitrypsin deficiency [AAT] are more likely to develop COPD symptoms).

Why Does COPD Get Worse?

Bacterial or viral infections cause half of all COPD exacerbations, while environmental variables are responsible for the other causes. The progression of COPD can be slowed by minimizing exacerbations and avoiding COPD triggers. The following are typical triggers for COPD both indoors and outside:

  • Tobacco smoke
  • Dust
  • Pet dander
  • Pollen
  • Stronger odors: perfumes, scented candles, and air fresheners
  • Chemical fumes: cleaning products, paints, and solvents
  • Pollution: outdoor pollution (vehicle exhaust, gas station fumes) indoor pollutants (fumes and odors from cooking, fireplace, dirty air filters
  • Extremes in temperatures: extreme heat or cold

Chronic Bronchitis

Chronic bronchitis is a common complication of COPD. Daily coughing due to chronic bronchitis results in mucus overproduction, recurrent viral or bacterial infections, and inflammation of the airways. The "smoker's cough" is most likely an indication of COPD and chronic bronchitis as smoking is frequently the cause of chronic bronchitis. Bronchodilators, steroids, and oxygen therapy are all possible forms of treatment for chronic bronchitis. It is also advised to stop smoking and steer clear of bronchial irritants in the air.


Emphysema is a lung condition. Alveoli, which are tiny air sacs in the lungs that help with carbon dioxide and oxygen exchange, suffer damage and eventually die in emphysema. As a result of the inability to exchange carbon dioxide and oxygen, the alveoli eventually die and leave holes in the lungs, leading to the loss of lung tissue and an increase in the symptoms of COPD. Emphysema symptoms may include shortness of breath, coughing, and wheezing. Oxygen, steroids, antibiotics, and bronchodilators are all possible emphysema treatments. Additionally, giving up smoking is extremely advised.

COPD Prognosis

For those with mild COPD, the prognosis is excellent, but it gets worse as the severity of stage rises. A COPD patient who receives a lung transplant has a five-year life expectancy on average. If they stop smoking, patients with COPD have a substantially better prognosis. The prognosis for COPD depends on the patient's health and the disease's stage.

The BODE Index

The COPD prognosis of a patient can be evaluated using the BODE Index. This examination takes into account the patient's body mass index (BMI), exercise tolerance, dyspnea, and airway obstruction as determined by the MMRC dyspnea scale (measured by a 6-minute walk). The BODE Index can estimate the lifespan of a COPD patient.

COPD Stages

COPD comprises four phases, and each stage has a unique set of symptoms. A pulmonary function test (PFTS) is typically required of patients when their COPD stage is determined.

Stage I (Mild COPD) Symptoms

  • Shortness of breath when hurrying or walking on a slight incline
  • No cough or mucus
  • PFT results are usually 80% or more

Stage II (Moderate COPD) Symptoms

  • Walking slower
  • Become breathless when walking
  • Possible cough or mucus
  • PFT results are 50%-80%

Stage III (Severe COPD) Symptoms

  • Stopping to regain breath after a few minutes of walking
  • Possible cough and/or mucus
  • Increased fatigue
  • PFT results are 30%-50%

Stage IV (Very Severe COPD) Symptoms

  • Too breathless to leave the house
  • Breathless during everyday tasks
  • Reduced quality of life
  • PFT results are less than 30%

COPD and Diet

The symptoms of COPD may be lessened with a nutritious diet. Being overweight can make it harder to breathe and perform daily tasks, while being excessively thin might leave you weak. You can get advice on a healthy diet for you from your doctor or a nutritionist. Here are some general dietary recommendations:

  • Avoid under and over eating
  • Monitor calories
  • Limit salt intake
  • Drink water, not caffeinated or carbonated drinks
  • Eat high fiber foods (bran, fresh fruit)
  • Avoid gas-producing foods (fried foods, beans)
  • Eat small meals (3) with healthy snacks (2-3) every day

Living With COPD

Living with COPD can be very challenging, but there are strategies to lessen symptoms and reduce the disease's development. Although many have already been mentioned in the slides that came before, here is a list of ways to enhance your day-to-day life:

  • Stop smoking
  • Eat a healthy diet
  • Stay active (exercise to improve your endurance)
  • Use your medications as directed
  • Get the flu vaccine every year and get vaccinated against pneumococcal pneumonia
  • The CDC advises patients with COPD on the use of face masks or coverings during any epidemic or pandemic caused by a respiratory pathogen. Use sanitary hand washing techniques, avoid people with respiratory infections or those who have symptoms (cough, sneezing, nasal drip), avoid crowds, and stay at home as much as possible during any such epidemic or pandemic.

If your COPD symptoms worsen or you start feeling feverish, see a doctor right away.